From the Ranch to System Dynamics:
Jay W. Forrester
Sloan School of Management
Massachusetts Institute of Technology
A chapter for
A Collection of Autobiographical Essays, Vol. 1
edited by Arthur G. Bedeian
Published by JAI Press, 1992
Edited, January 27, 2000
Copyright © 1991 and 2000
by Jay W. Forrester
Table of Contents
MY INTRODUCTION TO FEEDBACK SYSTEMS
PIONEERING IN DIGITAL COMPUTERS
MOVING TO MANAGEMENT EDUCATION
LAUNCHING SYSTEM DYNAMICS
EXTENDING SYSTEM DYNAMICS TO SOCIAL AND
WORLD DYNAMICS AND THE CLUB OF ROME
SYSTEM DYNAMICS NATIONAL MODEL
GROWTH OF THE SYSTEM DYNAMICS FIELD
A NEW KIND OF MANAGEMENT EDUCATION
STARTING AT THE BEGINNING--PRE-COLLEGE
HONORS AND AWARDS
SELECTED WORKING PAPERS
From the Ranch to System Dynamics:
Jay W. Forrester
Since 1956 I have had the
exciting and challenging opportunity to found and develop the
new field of system dynamics. System dynamics deals with how the
structure of a system and its information flows determine behavior--the
control of growth, stability, decay, success, and failure. The
field focuses on the way internal feedback-loop relationships
cause a system to change through time. Understanding why a system
behaves as it does permits redesign of structure and policies
to improve behavior. The ideas and methods of system dynamics
are applicable to natural, human, and technical systems. The field
combines theory and computer simulation with a very practical
application to real-world problems.
As I look back, I see that
my career evolved through several critical changes in direction.
When opportunities knocked, I was willing to give up the past
and turn in new directions. Each change led to pioneering in new
and more challenging arenas. With the succession of experiences
came the growing realization that new ideas will naturally be
met with skepticism. One must have the courage and persistence
to sustain a long-term vision against oppositions that arise along
the way. Everything that I have done converged to make the development
of system dynamics possible.
(Go to top.)
My childhood experiences
came from a cattle ranch in the Nebraska Sandhills located in
the middle of the United States. My father and mother were the
original homesteaders in about 1910 on that late-developing part
of the American frontier. (1)
- (1) M. M. Forrester (Marmaduke Montrose), known as "Duke,"
born January 3, 1883 in Emerson, Iowa, died April 19, 1975 in
Portland, Oregon; and Ethel Pearl Wright Forrester, born March
16, 1886 in Hastings, Nebraska, died December 27, 1958 in Portland,
Oregon. Children: Jay Wright Forrester, born July 14, 1918 at
Climax, Nebraska (no longer in existence, half way between Dunning
and Arnold), and Barbara Frances Forrester Sliger, born April
21, 1921, at Climax. See Susan S. Forrester, 1989, Descendants
of Oliver C. Forrester, Concord, MA: 29 King Lane 01742.
Shopping was 18 miles away
by horse and wagon. Although we lived in a concrete block house
with running water, most of our first neighbors built sod houses
from the top layer of the grass land. It was a community of pioneers
settling under the Kincaid Homestead Act, which allowed a square
mile of land per family. When early attempts to farm the thin
top soil failed, and most settlers left, those who stayed turned
to cattle ranching.
My parents were the only
people in the community with a college education. Dad had graduated
from Hastings College in Nebraska and had been a football player,
and on the track team, glee club, and debating society, while
also working as a newspaper reporter. Mother attended Hastings
College three years and then worked in libraries in Springfield,
Massachusetts and Jacksonville, Florida. In later years, the superintendent
of the Anselmo, Nebraska, high school, which I attended, described
his first visit to our home as the discovery of a cultural oasis
in the intellectual wilderness.
When they first settled
on the ranch, both my parents taught in one room country schools.
After she gave up her position as public school teacher, my mother
taught me at home during my first two years of school. Later,
I rode a horse a mile and a half to third and fourth grades at
a one-room school taught by my father. Women who had been my father's
students taught me in grades five through eight at the same school.
It was there that my interest in electricity started with experiments
on batteries, doorbells, and telegraphs. Inspiration came from
the Nebraska "traveling library" that sent a box of
books on loan to the school each year.
A ranch is a cross-roads
of economic forces. Supply and demand, changing prices and costs,
and economic pressures of agriculture become a very personal,
powerful, and dominating part of life. Furthermore, in an agricultural
setting, activities must be very practical. One works to get results.
It is full-time immersion in the real world. Children have their
regular chores as part of the family business. In such closely
knit activities, my parents guided learning and character development.
Although ranch obligations were demanding, I was fortunate in
being allowed time to develop interests that were not immediately
related to the daily needs.
While a senior in the Anselmo,
Nebraska, high school, I built a 12 volt wind-driven electric
plant that provided the first electricity on our ranch. It powered
the radio, lights in the house, and motors for shop work. Building
an electrical system from discarded automobile parts was a very
practical undertaking and another step in learning how to succeed
in uncharted territory.
On finishing high school,
I had received a scholarship to go to the Agricultural College,
when one of those important turning points intervened. Three weeks
before enrolling in agriculture, I decided it wasn't for me. Caring
for sick cattle and herding them in Nebraska winter blizzards
never had captured my enthusiasm. I had preferred the tractors,
machinery, and shop work. My parents had never tried to limit
my interests or direct my future vocation. So, I enrolled in the
Engineering College at the University of Nebraska. Electrical
engineering, as it turns out, was the only academic field with
a solid, central core of theoretical dynamics. The road began
toward my work in the behavior of systems.
Finishing at the University
brought another turning point. I came to the Massachusetts Institute
of Technology for two reasons. First, they offered me a $100 per
month research assistantship, which was more money than any other
university had offered. Second, my mother, from her library experience
in Springfield, Massachusetts, knew about MIT. In the high plains
of the United States at that time, "M.I.T." more often
implied salesmen for a financial institution, the Massachusetts
Investors Trust, than an engineering school.
(Go to top.)
MY INTRODUCTION TO FEEDBACK
In my first year at MIT
came another of the decisive branches in my career. I was employed
in 1940 as a research assistant by Gordon S. Brown when he founded
the Servomechanisms Laboratory and began to pioneer "feedback
control systems" at MIT for military equipment. During World
War II with Brown, I developed servomechanisms for the control
of radar antennas and gun mounts. Departing from my training in
electrical engineering, the work focused on designing mechanical
hydraulic variable speed pumps, motors, and high-gain hydraulic
amplifiers because at that time the military mistrusted vacuum
tubes in anything except radios. (2)
- (2) Brown and Forrester patent (1946).
Again, it was research
toward an extremely practical goal that ran from mathematical
theory of control and stability to the military operating field,
and I do mean the operating field. At one stage, we built experimental
hydraulic controls for a radar designed at the MIT Radiation Laboratory.
After redesign, the radar was intended for aircraft carriers to
direct fighter planes against enemy targets. The captain of the
carrier U.S.S. Lexington visited MIT and saw this experimental
unit, which was planned for production a year or so later. He
said, "I want that; I mean that very one; we can't wait for
the production equipment." He got it.
In the following nine months
the experimental laboratory radar had directed fighters in shooting
down some 20 enemy planes before they came close enough to see
the Lexington. But then, the experimental control units stopped
working. In November 1943, I volunteered to go to Pearl Harbor
to find the reason and repair the hydraulic controls.
Having discovered the problem,
but not having time to fix it, I was approached by the executive
officer of the Lexington who said they were about to leave Pearl
Harbor. He asked me to come with them to finish my job. I agreed,
having no idea where that might lead.
We were off shore during
the invasion of Tarawa and then took a turn down between the Ratak
and Ralik chains of the Marshall Islands. The islands on both
sides held enemy air bases, and the Japanese didn't like having
a U.S. Navy Task Force wrecking their airports. They kept trying
to sink our ships. Finally, twelve hours later and after dark
they dropped flares along one side of the task force and come
in with torpedo planes from the other side. About 11:00 PM, they
succeeded in hitting the Lexington, cutting through one of the
four propeller shafts and setting the rudder in a hard turn. Again,
the experience gave a very concentrated immersion in how research
and theory are related to practical end uses.
(Go to top.)
PIONEERING IN DIGITAL COMPUTERS
At the end of World War
II came yet another turning point for which I am indebted to Gordon
Brown. I had about decided either to get a job or start a company
in feedback control systems when Brown, who was my mentor for
many years at MIT, again intervened. He offered a list of projects
that he thought might be of interest. I picked the building of
an aircraft flight simulator. It was to be rather like an elaborate
aircraft pilot trainer. However, it was to be precise enough to
take wind tunnel data from a model of a proposed plane and predict
the behavior of the full scale airplane before construction.
The aircraft analyzer project
was promoted by Admiral Louis deFlorez of the U.S. Navy. deFlorez
was a flamboyant individual with a pointed waxed mustache. He
was apparently the only person who had somehow acquired standing
permission to land a sea-plane on the sailing basin in front of
MIT. He came to MIT on Alumni Day and the Metropolitan District
Police cleared the basin of sail-boats so he could land his sea
plane. He attended part of the program and, when the speeches
became boring, would rev up the seaplane engines and take-off
with the noise drowning out the program he was leaving behind.
The Admiral taught me a
number of helpful insights about dealing with government bureaucracies.
Later, when we were building a digital computer, we needed another
hundred thousand dollars to continue. The response from deFlorez
was "Impossible! That is above my approval authority and
too little to justify going to the Secretary of the Navy. You
must ask for either fifty thousand or two hundred thousand."
We chose the latter figure.
At this time, Gordon Brown
added a new dimension to my life by introducing me to Susan Swett.
We were married July 27, 1946. (3) My parents, Gordon Brown, and
Susan are the ones to whom I owe the most for whatever I may have
accomplished over an interval of seventy plus years. Susan has
given steadfast encouragement and sympathy, compensation for my
frequent insensitivity to others, tolerance for my often putting
work at the top of the priority list, and an uninterrupted supportive
- (3) Our children: Judith, 1948, graduated from Goucher College,
has been a teacher, world traveller, and most recently is living
on and managing our family ranch in Nebraska; Nathan Blair, 1950,
received a bachelor's degree from Oberlin and a Ph.D. in system
dynamics from MIT and is a consultant in the field; Ned Cromwell,
1953, has a B.Sc. and M.Sc. from MIT in electrical engineering,
was an engineer for several years at the Digital Equipment Corporation,
and more recently an engineer on the Alvin deep-sea research
submarine at the Woods Hole Oceanographic Institute.
The aircraft simulator
started as an analog computer. It took a year to decide that an
analog machine of that complexity would do no more than respond
to its own internal idiosyncrasies. An analog computer could not
deal with the problem at hand.
Still another critical
break in my career came when Perry Crawford, an MIT graduate and
then in the Special Devices Center of the Navy headed by Admiral
deFlorez, suggested that we shift our attention to the digital
computer field in which work was just beginning. Design of the
aircraft analyzer was recast around the untested concept of a
digital computer. But times were changing, the need for the aircraft
analyzer became less pressing, and military tactics were outgrowing
the capability of information handling by a human network operating
Beginning in 1947, the
MIT Digital Computer Laboratory, under my direction, designed
the Whirlwind I digital computer. (4) Whirlwind was the first
general-purpose digital computer at MIT. It filled two roles,
as a scientific computer and as an experimental laboratory for
testing the use of digital computers in military combat information
- (4) For the story of this pioneering program, see Kent C.
Redmond and Thomas M. Smith (1980), Project Whirlwind,
280 pages, Digital Press, Educational Services Division, Digital
Equipment Corporation, Bedford MA 01730.
The reader today with a
desktop computer can hardly appreciate the skepticism in the late
1940s to a suggestion that computers could ever be made to work
reliably, or that they would be needed even if they worked. One
computer pioneer of that time was quoted as saying that, if all
the five digital computers then under experimental development
should by any chance work, they would more than saturate any conceivable
need for such machines. Only the experience of having succeeded
in past pioneering programs and the belief that history would
repeat sustained us against the opposition of the doubters.
Robert R. Everett worked
with me from 1946 to 1956 as associate director of the Digital
Computer Laboratory and as associate division head in the Lincoln
Laboratory. I am greatly indebted to him for his technical skill
and his gift for leadership of an engineering organization. We
had started together in the early 1940s in the Servomechanism
Laboratory and shared the same background. After I left the computer
field in 1956, Everett continued to lead the organization we had
established together. That activity separated from MIT to become
the MITRE Corporation, from which Everett has recently retired
When development of Whirlwind
began, no satisfactory devices existed for high-speed internal
information storage. A few early computer projects chose onedimensional
storage, consisting of a tube of mercury, in which shock waves,
transmitted and received by crystals at the two ends, represented
binary digits in transit. Other computer projects based design
on two-dimensional storage in the form of cathode-ray tubes in
which digits were stored as positive and negative charges on the
inside faces of the tubes. But all these were slow or unreliable
My invention of the coincident-current
random-access magnetic computer memory in 1949 was a classic case
of necessity being the mother of invention. (5) I was responsible
for a computer development project and a mission in combat information
systems that could not succeed with the existing technology for
computer memory. The newly conceived and developed magnetic memory
was fast, completely reliable, and became the standard computer
memory for about 20 years until replaced by solid-state micro
- (5) See Forrester (1951), Digital Information Storage in
Three Dimensions Using Magnetic Cores, Journal of Applied
Physics; and Forrester (1956), Patent No. 2,736,880.
Again, the slow pace of
acceptance of new ideas was evident. It took us about seven years
to convince industry that magnetic-core memory was the solution
to a missing link in computer technology. Then we spent the following
seven years in the patent courts convincing them that they had
not all thought of it first.
From the Whirlwind computer
program came technology for the first practical digital control
of machine tools. For many years, numerical control in manufacturing
operated under the patent emerging from that early work. (6)
- (6) See Forrester, et al (1962), Patent No. 3,069,608, Numerical
Control Servo-System. For a history, see J. Francis Reintjes
(1991), Numerical Control: Making a New Technology, New
York: Oxford University Press.
In its final redefinition
of mission, the Whirlwind computer became a laboratory for exploring
how digital computers could serve as military combat information
centers. At a time when no high-speed digital computer had yet
operated reliably, such a proposal to use them to analyze and
control military operations was met with disbelief and hostility
by military officers who felt that only their training and field
experience could serve as a basis for handling military situations.
Such confidence in the earlier human-network handling of tactics
persisted in the face of clear evidence that speed and complexity
of military technology had far outstripped unaided human command
By gaining the support
of a few daring individuals in the military, it was possible to
carry on development until the merits of these seemingly radical
new proposals became evident. Professor George E. Valley of the
MIT physics department, who was chairman of the Air Defense System
Engineering Committee, played a key role in converging our proposals
for digital computers in command and control with financial support
from the U.S. Air Force, which was then seeking an improved air
Largely on the basis of
this early work, the MIT Lincoln Laboratory for air defense research
was formed. I headed Division 6 of Lincoln, which designed computers
for the SAGE (Semi-Automatic Ground Environment) air defense system
for North America. Valley headed the division handling the radar
side of the system. Whirlwind grew to become the nucleus of the
Experimental Cape Cod Air Defense System for demonstrating how
a digital computer could analyze and coordinate radar information
and issue directions to defensive weapons.
The SAGE air defense system
was another of those practical undertakings where theory and new
ideas were only as good as the working results. The SAGE system
had about 35 control centers, each 160 feet square, four stories
high, and containing upward of 60,000 vacuum tubes. Many people
had criticized the concept on the basis that such a large electronic
assembly would fail too often to be useful. Such a prediction
was reasonable based on prior engineering experience. Vacuum tubes
had a life of about 500 hours. Agreeing that such performance
would make our proposals inoperative, we undertook to discover
the reason that tubes had been failing, redesigned them to remove
the cause, and increased the average life by a thousand fold in
one design step. Even that was not enough. In addition, a "marginal
checking" system was incorporated that could find any deteriorating
electronic component before it reached the point of causing an
The SAGE computer centers
were installed in the late 1950s; the last was decommissioned
in 1983. They were in service about 25 years. Historical statistics
show that individual centers were operational 99.8% of the time.
That would be less than 20 hours a year that a center was out
of operation. Even today, such reliability is a challenging record
to match in military systems.
(Go to top.)
MOVING TO MANAGEMENT EDUCATION
Completion of the SAGE
system design coincided with another crucial incident and the
opening of another door of opportunity. James R. Killian, Jr.,
who was then president of MIT, brought a group of visiting dignitaries
to the Lincoln Laboratory. While we were walking down the hall,
Killian told me of the new management school that MIT was starting,
and suggested that I consider joining. Discussions over the next
several months with Associate Dean Eli Shapiro and Professor Edward
L. Bowles led to my becoming a full professor in management. It
was my first academic appointment; earlier work had all been on
the MIT research staff.
People often ask why I
made such an abrupt change as going from engineering to the Management
School. There were several reasons. By 1956, I felt the pioneering
days in digital computers were over. That might surprise readers
looking back on the major advances during the last 35 years. But
the multiple by which computers improved in speed, reliability,
and storage capacity in the decade from 1946 to 1956 had been
greater than the multiple in any decade since. Furthermore, moving
to a management school was not a break from a purely technical
background. I was already in management.
We had been running a vast
operation in which we had control from basic research to military
operational planning. We wrote the contracts between the participating
corporations and the Air Force. We designed the computers with
full control over what went into production. We defended the Air
Force's budget before the Bureau of the Budget because the technology
was so new that it was outside the experience of the military
commands. We had been managing an enterprise that involved the
Air Defense Command, the Air Material Command, the Air Research
and Development Command, Western Electric, A.T.&T., and I.B.M.
The move from Lincoln Laboratory was not so much a radical change
as a shift to a different perspective from which to view management.
The MIT School of Management,
later to be renamed the Sloan School, had been founded in 1952
with a grant of ten million dollars from Alfred P. Sloan, Jr.,
the man who built the modern General Motors Corporation. The money
was given with the expectation that a management school in a technical
environment such as MIT would develop differently from one in
a liberal arts environment like Harvard, or Columbia, or Chicago.
Such a school might be better, but in any case different, and
Sloan believed it worth ten million dollars to run the experiment.
In the four years before
I joined the School in 1956, standard management courses existed,
but nothing had been done about the concept of a management school
within an engineering environment. By that time, I had 15 years
of participation in the science and engineering side of MIT and
bringing that background to bear on management offered an interesting
Others, and probably I
also, assumed that an application of technology to management
meant either to push forward the field of operations research,
or to explore the use of computers for the handling of management
information. My first year was free of other duties except to
decide why I was at the Management School. On computers for management
information, activity was growing rapidly among manufacturers
of computers, and banks and insurance companies were actively
using computers. It did not seem that a few of us in a management
school would have major impact on the already existing momentum.
Regarding operations research, it seemed interesting; it no doubt
was useful; but it was not working with issues that made the difference
between corporate successes and failures. Operations research
did not have that compelling practical importance that had always
characterized my work.
(Go to top.)
LAUNCHING SYSTEM DYNAMICS
Again chance intervened
when I found myself in discussions with several people from General
Electric. They were puzzled by why their household appliance plants
in Kentucky sometimes worked at full capacity with overtime and
then two or three years later, half the people would be laid off.
It was easy enough to say that business cycles caused fluctuating
demand, but that explanation was not entirely convincing.
After talking with the
manufacturing people about how they made hiring and inventory
decisions, I started to do some simulation. The analysis based
on the feedback viewpoint from my earlier experience used very
simple simulations with pencil and paper on a notebook page. The
computation started at the top with columns for inventory, employees,
production rate, backlog, and orders. Given these initial conditions
and the policies being followed in manufacturing, one could enter
how many people would be hired in the following week. Because
of time delays and trend projections, production did not adjust
smoothly to demand.
A fluctuating (oscillatory)
response would follow a small change in demand. The internal structure
and policies defined a manufacturing system that tended toward
unstable behavior. Even with constant incoming orders, employment
instability could result from commonly used decision making policies.
That first inventory control system with pencil and paper simulation
was the beginning of system dynamics. (7)
- (7) See Forrester (1957), Systems Technology and Industrial
Dynamics; and (1958), Industrial Dynamics--A Major Breakthrough
for Decision Makers.
Viewed in the context of
management research, the social sciences, and economics, system
dynamics differs in having been developed through intimate contact
with the real worlds of practicing management and politics. System
dynamics shows how structures and policies, which are well known
in the operating arenas, can produce the successes and difficulties
that are being experienced.
My Industrial Dynamics
book in 1961 first presented the philosophy and methodology of
system dynamics. The book grew partly out of teaching Sloan Fellows
who are managers age 30 to 40 with substantial corporate and managerial
experience. Their master's theses explored many dynamic business
issues, including commodity markets, evolution of nuclear energy,
military research and development management, corporate growth,
and design lead time and market penetration in the automobile
industry. The book also benefited from our teaching two-week intensive
summer session programs for managers. At the same time, we developed
the systems concepts while applying them in sponsored corporate
research projects that formed a meeting ground for theory and
An example of the close
linkage of practice and analysis arose in my early excursions
into the dynamics of corporate growth. (8) At the time system
dynamics was starting, I joined the board of the Digital Equipment
Corporation. The founders of the company offered the invitation
because they had worked with me in the Whirlwind computer days.
- (8) See Forrester (1964), Common Foundations Underlying Engineering
and Management; (1966), Modeling the Dynamic Processes of Corporate
Growth; and (1968), Market Growth as Influenced by Capital Investment.
I did not understand the
nature of high technology growth companies as well as I felt I
should as a board member. Also, if the emerging field of system
dynamics was as powerful as we believed, it should shed light
on why new companies exhibit such widely varying degrees of success.
I undertook to model the general nature of high-technology growth
companies to guide my own position on the board.
From the modeling came
a number of insights about why high technology companies often
grow to a certain level and then stagnate or fail. This modeling
of corporate growth moved system dynamics out of physical variables
like inventory into much more subtle considerations. Over 90%
of the variables in that corporate growth model lay beyond the
usual tangible variables. They included the top-management influence
structure, leadership qualities, character of the founders, how
goals of the organization are created, and how the past traditions
of an organization determine decision making. The model also dealt
with the interactions between capacity, price, quality, and delivery
In our corporate work on
how structure and policies determine behavior, we found we could
go into a troubled company and uncover the reasons for its problems.
The difficulty might be falling market share, or fluctuations
in production with employment varying from working overtime one
year to having half the work force laid off two years later, or
a lower profitability than other companies in the industry. Such
difficulties are widely known to employees, the community, and
the business press.
Our background about how
feedback loops relate to behavior guides examination of a company.
Information comes from interviewing people about how they make
decisions at their individual operating points. These statements
describing the basis for decisions are the rules or policies governing
action. As I use the term "policy," it represents all
the reasons for action, not just formal written policy.
These interviews are extensive
and penetrating. There may be several sessions with each of many
individuals. The discussions range widely from normal operations,
to what is done in various kinds of crises, what is in the self
interest of the individual, where are the influential power centers
in the organization, what would be done in hypothetical situations
that may have never been experienced, and what actions are being
taken to help in solving the serious problem facing the company.
We find that talking to
a manager can reveal a clear and comprehensive picture of the
rules and conditions driving decisions at that position in the
corporation. Then, when one talks to another manager about the
first manager, the same picture usually emerges. In other words,
people see themselves very much as others see them. There is substantial
consistency throughout the organization as to the actual operational
policies that are guiding decisions. Furthermore, the policies
are usually justified in terms of how those policies are expected
to help overcome the great difficulty that the company is experiencing.
During this interview stage,
the examination of such a company follows the case-study approach
used in management education. That is, a comprehensive examination
of all related parts of the company is made in the context of
the problem that is to be solved. The pieces of the picture are
described in words. But, if left at this point, the weakness of
the case-study method would intrude and dominate the outcome.
A descriptive model of the company would have been assembled,
but the human mind is not able to deal with the inherent dynamic
complexity of such a situation.
For readers who have studied
mathematics through differential equations, such a descriptive
case-study type of model is equivalent to a high-order nonlinear
differential equation. No scientist or mathematician can solve
such a system mentally. Just as with the operation of a chemical
plant, only computer simulation methods are capable of revealing
the behavior implicit in the structure built from knowledge about
the many local decision-making individuals and their linkages.
After obtaining a description
of the important policies, information flows, and interconnections
in a company, the next step translates that description into a
computer simulation model. Such a model allows the computer to
act out the roles of each decision point in the corporate system
and feed the results to other connected decision points to become
the basis for the next round of decisions. In other words, a laboratory
replica of the company then exists in the computer where one can
observe the behavioral consequences of the policies that were
described in the interviews--policies that were intended to solve
the company's problem.
To the surprise of those
unfamiliar with the devious nature of such dynamic systems, a
computer model, based on policies known to people in the company,
will generate the very difficulties that the company has been
experiencing. In short, the policies that are expected to solve
the problem are, instead, the cause of the problem. Such a situation
creates a serious trap and often a downward spiral. If the policies
being followed are believed to alleviate the problem, but, in
hidden ways, are causing the problem, then, as the problem gets
worse, pressures increase to apply still more strongly the very
policies that are causing the problem.
(Go to top.)
EXTENDING SYSTEM DYNAMICS TO
SOCIAL AND ECONOMIC BEHAVIOR
A series of incidents in
1968 moved my work from corporate modeling to broader social systems.
John F. Collins, who had been mayor of Boston for eight years,
decided not to run for reelection. MIT gave him a temporary appointment
as Visiting Professor of Urban Affairs to bring him into the academic
orbit as a way to meet students, interact with faculty, and advise
the administration on political issues.
Collins had been a victim
of polio in the Massachusetts epidemic of the mid 1950s and walks
with two arm canes. He needed an office in a building with automobile
access to the elevator level. The building with my office was
one of the few that qualified. The professor next door to me was
away for a sabbatical year, so John Collins was assigned the adjacent
In discussions with Collins
about his many years of coping with Boston urban problems I developed
the same feeling that I had come to recognize in talking to corporate
executives. The story sounded plausible but it left an uneasy
sense that something was wrong or incomplete or being misinterpreted.
So, I suggested to Collins that we might combine our efforts,
taking his extensive practical experience in cities and my background
in modeling, and look for interesting new behavioral insights
about cities. He immediately asked how to go about it.
I told Collins that we
would need advisers who knew a great deal about cities from personal
experience, not those whose knowledge came only from academic
study and reading. We needed people who had struggled with cities,
worked in them, and knew what really happens. And furthermore,
we would not know what would come of the effort, or how long it
might take. The process would be to gather a group that would
meet half a day a week, probably for months, to seek insights
into those urban processes that could explain stagnation and unemployment.
Collins listened and said,
"They'll be here on Wednesday afternoon." Collins' position
in Boston then was such that he could phone almost anyone in politics
or business, and get a commitment of time for a half day per week.
He delivered the people. It was out of the following discussions
over an interval of six months that the Urban Dynamics
Urban Dynamics was
the first of my modeling work that produced strong, emotional
reactions. The model simulations suggested that the major United
States policies all lay somewhere between neutral and highly detrimental,
either from the viewpoint of the city as an institution, or from
the viewpoint of the low-income, unemployed residents.
Our examination of urban
behavior showed that the most damaging policy was to build low-cost
housing. At that time, building low-cost housing was believed
essential to reviving the inner cities. But the construction of
low-cost housing occupies land that could have been used for job-creating
structures, while at the same time the added housing draws in
people who need jobs. It creates a social trap that increases
unemployment, and reduces the economic vitality of both the city
and the individual residents.
Although I believe the
Urban Dynamics book has survived the test of time, the
conclusions offended many people around 1970. When the book first
appeared, one faculty colleague came to me and said, "I don't
care whether you are right or wrong, the results are unacceptable."
So much for academic objectivity! Others, probably believing the
same thing, put it more acceptably as, "It doesn't make any
difference whether you're right or wrong, urban officials and
the residents of the inner city will never accept such ideas."
It turned out that those were the two groups we could count on
for support if they became sufficiently involved to understand.
That is a very big "if," if they came close enough to
Three to five hours were
required to understand what the urban dynamics model was revealing.
Urban officials and members of the black community in the inner
city became increasingly negative and emotional during those introductory
hours. If they had not been in a captive audience, they would
have walked out before they understood and accepted the way in
which low-cost housing is a double-edged sword for making urban
conditions worse. Constructing low-cost housing drives a powerful
process for creating poverty, not alleviating it.
My first experience with
reactions to Urban Dynamics came soon after the book was
published. The Sloan School had been running a four week program
for urban executives twice a year for department-head level people
from larger cities to teach various aspects of management. A group
was convening shortly after Urban Dynamics came out and
organizers of the program asked me to take a Monday afternoon
and a Wednesday morning to present the Urban Dynamics story.
I have never had a lecture
on any subject, any place, at any time go as badly as that Monday
afternoon. In the group was a man from the black community in
New York who was a member of the city government. He was from
Harlem, intelligent, articulate, not buying a thing I was saying,
and carrying the group with him.
At one point he said, "This
is just another way to trample on the rights of the poor people
and it's immoral." At another point he said, "You're
not dealing with the black versus white problem, and if you're
not dealing with the black versus white problem, you're not dealing
with the urban problem." And when I explained how decay and
poverty in Harlem in New York or Roxbury in Boston had been worsened
by too much low-cost housing, he said, "I come from Harlem
and there's certainly not too much housing in Harlem." Those
are samples of the afternoon.
On Tuesday evening, the
group met for dinner. Neither Collins nor I could go; but several
of our students attended. One student called me at home after
dinner to report what was rather obvious anyway--that the group
was very hostile. On that bit of encouragement, I started Wednesday
An hour into Wednesday
morning, the New Yorker's comments began to change character.
He was no longer tearing down what was being said. His questions
began to elicit information. Two hours into the morning, he said,
"We can't leave the subject here at the end of this morning.
We must have another session." I ignored the request to see
what would happen next. In about twenty minutes, he repeated it.
I agreed to meet them again if he could find a time and place
in the crowded program. I was not trying to put him off, but that
usually ends such an exchange. However, he persisted and went
to the administration and arranged another session.
Later the New Yorker made
an appointment to come to my office to ask that I talk to a group
he would invite in New York--his colleagues on his home turf.
He sat in my office completely relaxed and said, "You know,
it's not a race problem in New York at all, it's an economic problem."
Four days earlier he had asserted that I was not even addressing
the urban problem if not dealing with the black versus white issue.
He gave me a report out of his brief case documenting the amount
of empty housing in every borough of New York, including Harlem,
and the rate of abandonment. My point in saying there was too
much housing meant that there was too much for the economy of
the area to support. He had all the proof right in his brief case.
He simply had not realized what his knowledge meant until it was
all put together in a new way.
Two years later a journalist
asked me what people thought in the aftermath of Urban Dynamics.
I suggested that he talk to others, and especially with the man
in New York whom I had not contacted in the intervening two years.
After the interview, the journalist phoned to say he had been
told "they don't just have a solution to the urban problem
up there at MIT, they have the only solution." The lesson
about urban behavior had stayed clear and alive for two years
even back home in his political environment. The five hours of
exposure to Urban Dynamics had made a lasting impression.
But we have not solved the challenge of how to bring enough people
across the barrier separating their usual, simple, static viewpoint
from a more comprehensive understanding of dynamic complexity.
Urban Dynamics led
to both the World Dynamics and Limits to Growth
projects and to the System Dynamics National Model program.
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WORLD DYNAMICS AND THE CLUB
The urban work initiated
my contact with the Club of Rome. I met Aurelio Peccei, the founder,
at a meeting on urban difficulties held in Italy at Lake Como
in 1968. Later, after being asked to join, at a meeting of the
Club in June 1970 in Bern, Switzerland, came another turning point
in my career with system dynamics. What followed is more fully
described in the introduction to World Dynamics.
The "world problematique"
discussed at the Bern meeting became the basis for the model in
World Dynamics. In the three weeks after the Bern meeting,
I created the model for World Dynamics and 80 pages of
text. This material became the centerpiece for a two-week meeting
with the executive committee of the Club of Rome at MIT in July
1970. Included in the group was Eduard Pestel, president of the
Technical University of Hannover. Pestel was a very forceful person
and quickly saw the power of system dynamics. The executive committee
decided to finance research at MIT to go beyond the material that
had been presented at the meeting. Pestel arranged for the Volkswagen
Foundation to support work that resulted in the Limits to Growth
- (9) Donella H. Meadows, et al (1972), The Limits to Growth,
New York: Universe Books.
The public responses to
system dynamics have always surprised me. People ask what I think
the reaction will be when the National Model books are released.
I don't know. Usually I have been wrong in anticipating the effect
that system dynamics books will have.
In 1971 when World Dynamics
first appeared, the book seemed to have everything necessary to
guarantee no public notice. First, it had forty pages of equations
in the middle, that should be sufficient to squelch public interest.
Second, the main messages were presented as computer output graphs,
and most of the public does not understand such presentations.
Third, the publisher of the book had published only one previous
book and I doubted that World Dynamics had the commercial
status even to be reviewed. I intended the book for maybe 200
people in the world who would like to study an interesting model
on their computers. The book showed the long-term interplay of
population, industrialization, resource depletion, agriculture,
and pollution. But, I was wrong about the audience.
World Dynamics came
out the first week of June 1971. The last week of June, it was
reviewed in the London Observer, which then circulated
around the world. A letter from a professor in New York asked
for more information because he had been reading about the book
in the Singapore Times! In August the book had the full
front page of the second section of the Christian Science Monitor,
in September a page and a half in Fortune, and in October
a column in the Wall Street Journal. It was running through
editorial columns of mid-America newspapers, and was the subject
of prime time documentary television in Europe. It was debated
in the environmental press, the zero population growth press,
and the antiestablishment underground student press.
And, for those not liking
their literature on either the establishment right or the establishment
left, then in the middle of the political spectrum, the World
Dynamics book was the subject of a full-length article in
Playboy. But as a communications medium for conveying system
dynamics, that magazine was a disappointment. Out of eight million
copies printed, the only response I received was a request to
conduct a two-day meeting for the Board of Overseas Missions after
the article was read by a man at the National Council of Churches.
Nine months after World
Dynamics appeared, Limits to Growth was published.
The message was essentially the same, although much more research
and verification had been done. The book was more popularly written,
but even so, after the earlier attention from the media, it seemed
that the second book could only be an anti-climax. The results
showed that one can be wrong twice in succession in exactly the
same way. Public attention jumped another factor of ten after
appearance of Limits to Growth.
The two books gained wide
visibility and created great controversy. Limits to Growth
has sold several million copies and been translated into about
thirty languages. Due to the system dynamics approach, the books
were able to clarify issues that troubled the public and that
people wanted to understand better.
As with earlier modeling,
reactions surprised us. Who would react to rising environmental
pressures that will progressively restrain growth of population
and industrialization over the next fifty years? We assumed the
subject would be anathema to chief executives of corporations.
On the other hand, we expected little interest in the social sciences.
Wrong on both. On the whole, the books received favorable responses
from chief executives of corporations, members of Congress, and
by young people. Disparagement often came from middle-level managers,
the Executive Department of the U.S. Government, and economists.
were the bitter and emotional attacks on the two books by many
economists. We would have thought the books lay outside their
area of interest until we realized that the books threatened the
underlying theology supporting the belief that growth can continue
forever. Even though largely unjustified, such published criticisms
have left their impact, especially on people who have not read
One now occasionally sees
newspaper comments referring to the "discredited Limits
to Growth," while in that paper are articles about acid
rain, water shortage in California, forests dying of pollution,
threatened species, and the debate about global warming; all illustrating
the central message of the books about the dynamics that result
from growth in population and industrialization overrunning the
world's environmental capacity.
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SYSTEM DYNAMICS NATIONAL MODEL
As this is written in February
1991, I am completing a long program of applying system dynamics
to understanding the behavior of national economies. Two books
are under way to set forth what we have learned.
The Urban Dynamics
book led to our work on the System Dynamics National Model. After
a talk at a joint NATO/US conference on cities in Indianapolis,
Indiana in 1971, William Dietel, now recently retired as president
of the Rockefeller Brothers Fund, came up from the audience to
discuss their future programs. From that meeting came initial
funding for our work in applying system dynamics to behavior of
economic systems. Since then, the work continued with private-sector
support from individuals and corporations.
The approach is very different
from the conventional econometric models, which are structured
on the basis of macroeconomic theory with parameters drawn from
statistical analysis of historical data and with a heavy dependence
on exogenous time-series to drive the dynamics of the model. From
the system dynamics view point, econometric models are essentially
curvefitting exercises. They do not contain the essential feedback
structures that create the kinds of dynamic changes that are seen
in real economies.
As with all my earlier
work, the emphasis has been on connecting research to actual practices
in the operating world. In that tradition the National Model contains
policies that can be observed in managerial practice in corporations,
banking, households, and government.
The results are far exceeding
our original expectations. The model generates endogenously the
major kinds of behavior that have been observed in actual systems--business
cycles, inflation, stagflation, growth, and the economic long
wave or Kondratieff cycle. Business cycles have peaks of activity
three to 10 years apart. The longer Kondratieff cycle has much
larger economic deviations with peaks spaced 45 to 60 years.
The National Model supplies
for the first time a theory for the economic long wave, which
we believe accounts for the great depressions that occurred around
1830, 1890, and in the 1930s. The long wave arises from major
interactions among capital investment, saving, monetary policy,
real interest rate, and speculation. It generates severe economic
downturns at five-to-seven-decade intervals.
As with prior work, we
can anticipate that publication on the dynamics of economic systems
will generate controversy because the results differ with previous
understandings about how economic behavior arises. Also the approach
suggests a very different way of looking at the study of economic
systems. Instead of thinking of economics as a social science,
we believe that the study of economics should be seen as a systems
profession comparable to engineering, management, and medicine.
Like the analysis and design of a chemical plant, understanding
an economy should be based on identifying the internal structure
of the system. The parts can then be interrelated in a simulation
model to demonstrate how they interact to generate observed, economic
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GROWTH OF THE SYSTEM DYNAMICS
It is gratifying to see
how the work that started in 1956 has grown into an active profession.
The System Dynamics Society has a worldwide membership and publishes
the System Dynamics Review. (10) Educational programs in
the field exist in a number of countries. Annual international
conferences move from country to country.
- (10) Available from John Wiley & Sons, England.
- (Go to top.)
A NEW KIND OF MANAGEMENT EDUCATION
Throughout its development,
system dynamics has offered a basis for a much improved kind of
management education. The suggestion has been resisted for a number
of reasons. It would break down the boundaries between academic
disciplines. It would undermine the assumption that doing the
"best" as viewed from within each separate functional
area is best for the organization as a whole. It would tend to
force faculty members to understand other disciplines and how
those other disciplines relate dynamically to their own. Also,
the approach depends heavily on knowledge about structure and
policies obtained directly from participants in actual corporate
practice, but in academia, such sources are often distrusted and
seen as being nonscientific.
However, if the goal is
worthwhile, patience and persistence prevail in time. There is
clearly a movement toward seeing management success as depending
on the interaction of many policies. There is a widening understanding
that analysis of individual policies will not reveal the behavior
of the whole.
An improved understanding
of corporate systems points the way to a future advancement in
management education. Beyond that, it suggests a new kind of manager
for the future. One can now see clearly a kind of management education
that we might call "enterprise design." And in the future
there is a role for the output of such an education, the "enterprise
- (11) See Forrester (1988) Designing Social and Managerial
Systems, and (1985) System Dynamics in Management Education.
A fundamental difference
exists between an enterprise operator and an enterprise designer.
To illustrate, consider the two most important people in the successful
operation of an airplane. One is the airplane designer and the
other is the airplane pilot. The designer creates an airplane
that the ordinary pilot can fly successfully. Is not the usual
manager more a pilot than a designer? A manager runs an organization.
Often there is no one who consciously and intentionally fills
the role of organizational designer.
Organizations built by
committee, by intuition, and by historical happenstance often
work no better than would an airplane built by the same methods.
Time after time one sees venture capital groups backing new enterprises
in which the combinations of corporate policies, characteristics
of products, and nature of the markets are mismatched in a way
that predetermines failure. Like a bad airplane design that no
pilot can fly successfully, such badly designed corporations lie
beyond the ability of real-life managers.
Management education, in
all management schools, has tended to train operators of corporations.
But there has been rather little academic attention to the design
of corporations. The determination of corporate success and failure
seldom arises from functional specialties alone, but grows out
of the interactions of functions with one another and with markets
and competitors. Management education underemphasizes policies
governing such interactions.
We need to deal with the
way policies determine corporate stability and growth in an intellectual,
challenging, quantitative, and effective way. Such management
education leads to what I refer to as enterprise design. Such
an education would combine two innovations that have developed
separately in this century.
The first innovation came
from the Harvard Business School, which pioneered the case-study
method of management education around 1910. The case method has
achieved a wide following because it addresses the problems of
general management and the interactions among parts of the corporate-market-competitor
system. The case method also draws great strength from being based
on the full range of descriptive information and the mental data
base of practicing managers. But the case method, has a major
weakness. The description of a case captures policies and relationships
that describe a system so complex that it can not be reliably
analyzed by discussion and intuition. Such attempts often draw
the wrong dynamic conclusions and fail to reveal why corporations
in apparently similar situations can behave so differently.
The second innovation,
the understanding of the dynamics of feedback systems, emerged
from engineering to become an organizing concept for human systems
as well. Feedback processes govern all growth, fluctuation, and
decay. They are the fundamental generators of all change. They
allow new insights into the nature of managerial and economic
systems that have escaped past descriptive and statistical analysis.
System dynamics modeling can organize the descriptive information,
retain the richness of the real processes, and build on the experiential
knowledge of managers. A simulation model reveals the variety
of dynamic behaviors that follow from different choices of policies.
I anticipate this will become the frontier of new developments
in management education during the next twenty years.
Bringing these two innovations
together offers the potential for a major breakthrough in management
education. The combination will permit going far beyond the case-study
method of management education by adding a rigorous dynamic dimension
to the rich policy and structural knowledge possessed by managers.
The difference between present and future management schools will
be as great as the difference between a trade school that trains
airplane pilots and a university engineering department that trains
Pilots continue to be needed,
and so will operating managers. But just as successful aircraft
come from skilled airplane designers, so in the future will successful
corporations rely on enterprise designers. Competition will force
reduction in the number of design mistakes in the structure and
policies of our social institutions.
Correct design can make
the difference between a corporation that is vulnerable to changes
in the outside business environment and one that exhibits a high
degree of independence from outside forces. Correct design can
improve the stability of employment and production. Correct design
in the balance of policies for pricing, capital plant acquisition,
and sales force, can often make the difference between growth
burdened by debt and growth out of earnings. Correct design can
help avoid the adoption of policies offering short-term advantage
at the expense of longterm degradation. Correct design can help
prevent expenditure of managerial time in debating policies that
are inherently of low leverage and therefore unimportant. Correct
design can help identify the very small number of high-leverage
policies capable of yielding desirable change.
Future training in enterprise
design will include study of a library of generic management situations
combining descriptive case studies with dynamic computer models,
each of which has wide applicability in business. I estimate that
about 20 such general, transferable, computerized cases would
cover perhaps 90 percent of the situations that managers ordinarily
encounter. Several powerful examples already exist. They include
a model of stability and fluctuation in a distribution system,
(12) a model of capital investment as it often restricts growth,
(13) a model of promotion chains and the evolution into a top-heavy
distribution of management personnel when growth slows, and a
model dealing with imbalances between design, production, marketing,
and service as these influence market growth. Each such model
manifests many modes of behavior ranging from troublesome to successful
depending on the policies employed within it.
- (12) See chapters 2, 15, and 16 in Forrester (1961), Industrial
- (13) See Forrester (1968), Market Growth as Influenced by
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STARTING AT THE BEGINNING--PRE-COLLEGE
Slowly over the years,
we have come to realize the difficulty people face in making the
transition to a dynamic and systems view of the world around them.
After writing Industrial Dynamics, I thought the task of
showing how policies and structure could be analyzed to understand
corporate change was finished. It seemed that managers and educators
would quickly pick up and begin to apply the concepts of feedback
behavior, simulation of policy interactions, and corporate design.
For several years I even turned my attention to quite different
activities, feeling that nothing more would be needed. Not only
was that optimism unjustified, but later efforts in system dynamics
have repeatedly shown the high hurdle to cross in drawing people
to the dynamic viewpoint when they were already mature in established
statistical, or open-ended, or static views of their surrounding
Understanding dynamic behavior
comes slowly. No single learning process suffices. One can encounter
feedback dynamics in the form of mathematical differential equations,
in computer simulations, in physical laboratory experiments, and
in informed observation of surrounding natural and social processes.
But no one of these suffices, and even a combination does not
immediately produce insights.
In corporate consulting,
it can take several years for a management to understand and accept
the way in which their own policies are creating the problems
that they are experiencing. By that time, the individuals have
often retired or died, and one faces a new oncoming generation
of managers and must start over.
It now seems clear that
we are asking for a paradigm transition of the kind discussed
by Kuhn. (14) Such a transition tends to be strongly resisted
both because it contradicts past assumptions and because it is
difficult to understand from within the prior perspective. A pessimistic,
but not entirely unrealistic, picture of paradigm revision suggests
that adherents to an older paradigm are seldom converted; instead,
they are in time replaced.
- (14) Thomas S. Kuhn (1962, second edition 1970), The Structure
of Scientific Revolutions, Chicago: University of Chicago
If then we hope for a time
when managers and political leaders possess a more effective grasp
of how their actions affect the future, what are we to do? The
educational system compartmentalizes knowledge, hides the unity
of systemic interactions, and teaches facts at the expense of
synthesis. By so doing, it creates a paradigm that becomes progressively
harder to alter as the individual develops.
Without the cause having
been clearly identified, I believe much of the current dissatisfaction
with pre-college education arises from past inability to show
things whole, to convey how people and nature interact, and to
reveal causes for what students see happening. Education is becoming
less relevant as society becomes more complex, crowded, and tightly
Education is fragmented.
Social studies, physical science, biology, and other subjects
are taught as if they were inherently different from one another
even though dynamic behavior in each rests on the same underlying
concepts. For example, the dynamic structure that causes a pendulum
to swing is identically the same as the core structure that causes
employment and inventories to fluctuate in a production distribution
system or in economic business cycles. Humanities fail to relate
the dynamic sweep of history to similar behaviors on a shorter
time scale that a student can experience in a week or a year.
High schools teach a curriculum
from which a student is expected to synthesize a perspective and
framework for understanding the social and physical environment.
But that framework is never explicitly taught. A student is expected
to create a unity from the fragments of the educational experience.
But the teachers themselves have seldom achieved that unity.
Missing from most education
is a direct treatment of the time dimension. What causes change
from the past to the present and the present to the future? How
do present decision-making policies determine the future toward
which we are moving? How are the lessons of history to be interpreted
to the present? Why are so many corporate, national and personal
decisions ineffective in achieving the intended objectives? Conventional
educational programs seldom offer such understanding. Answers
to questions about how things change through time lie in the dynamic
behavior of social, personal, and physical systems. Dynamic behavior,
common to all systems, can be taught as such. It can be understood.
The educational system
has been teaching static snapshots of the real world. But the
world's problems are dynamic. The human mind grasps pictures,
maps, and static relationships in a wonderfully effective way.
But in systems of interacting components that change through time,
the human mind is a poor simulator of behavior. Yet, even a junior
high school student with a personal computer and coaching in dynamic
behavior can advance remarkably far in understanding such complex
In system dynamics, understanding
how things change through time is facilitated by using the process
of integration (or accumulation) rather than differentiation as
the foundation for dynamic behavior. Those in science and technology
formulate most dynamic behavior in terms of differential equations.
But a derivative is a difficult concept to understand. Differentiation
is obscure because it is no more than a figment of the mathematician's
imagination. Nowhere does nature take a derivative. Nature only
integrates. Any child who can fill a water glass or take toys
from a playmate knows what accumulation (or integration) means.
By going directly in computer simulation to the real-life structures
involving integration, the procedure seems entirely natural and
Education faces the challenge
of undoing and reversing much that a person has learned by observation
of simple dynamic situations. Simple experiences in everyday life
deeply ingrain lessons that are deceptively misleading in dealing
with more complex social systems. For example, from burning a
hand on a hot stove, one learns the lesson that cause and effect
are closely related in both time and space--the hand is burned
here and now. Almost all understandable experiences reinforce
the belief that causes are closely related to results in time
and location. But in more complex systems, the cause of a difficulty
is usually far distant in both time and space--the cause lies
back in time and in a different part of the system from the point
where the symptoms appear.
To make matters even more
misleading, a complex feedback system presents what we have come
to expect, an apparent cause that lies close in time and space
to the symptom. However, that apparent cause is usually only a
coincident symptom through which there is little leverage for
producing improvement. Education does little to prepare students
for living successfully when simple, understandable lessons so
often point in exactly the wrong direction in the complex real
In his penetrating discussion
of the learning process, Bruner states, "The most basic thing
that can be said about human memory... is that unless detail is
placed into a structured pattern, it is rapidly forgotten."
(15) For most purposes, such a structure is inadequate if it is
only a static framework. The structure should show the dynamic
significance of the detail--how the details are connected, how
they influence one another, and how past behavior and future outcomes
result from decision-making policies and their interconnections.
- (15) Jerome S. Bruner (1963), The Process of Education,
p. 24, New York: Vintage Books.
System dynamics can provide
that dynamic framework to give meaning to detailed facts, sources
of information, and human responses. Such a dynamic framework
provides a common foundation beneath mathematics, physical science,
social studies, biology, history, and even literature. (16)
- (16) I have recently been moved to add literature to this
list after reading about the powerful impact on students from
a computer simulation of the psychological dynamics in Shakespeare's
Hamlet done by Pamela Hopkins, an eleventh-grade English
teacher at the Desert View High School in Tucson, Arizona.
Several high schools, curriculum-development
projects, and colleges are beginning to build study units in mathematics,
science, social studies, and history around a system dynamics
core. These have not yet reached the point of becoming a fully
comprehensive educational structure. Some other countries (Norway,
Germany, Japan, and China) appear to be moving ahead in using
system dynamics as a foundation for designing a more powerful
educational system below the college level.
Such exposure to dynamic
thinking should start at an early age before contrary patterns
of thought have become inflexibly established. Apparently exposure
to cause-and-effect feedback thinking and computer modeling can
successfully begin in schools for students around ten years old.
- (17) The earliest exploration of system dynamics at the fifth
and sixth grade levels was started by Nancy Roberts (1978), Teaching
Dynamic Feedback Thinking: An Elementary View, Management
Science, Vol. 24, No. 8, April.
Through the efforts of
Barry Richmond (18) and others, system dynamics is now being established
in some twenty junior and senior high schools. Macintosh computers
and the STELLA software are particularly user friendly and suitable
for pre-college education.
- (18) Barry Richmond, Ph.D. in system dynamics from MIT, president,
High Performance Systems, supplier of the STELLA software, 45
Lyme Road, Hanover, NH 03755.
I have described my introduction
to feedback systems by Gordon S. Brown in the MIT Servomechanisms
Laboratory in the early 1940s. Brown later became head of the
Electrical Engineering Department and then Dean of Engineering
before retiring in 1973. In the late 1980s, Brown has completed
the circle by picking up system dynamics and introducing it into
the Orange Grove Junior High School in Tucson, Arizona, where
he spends the winters. He started by loaning a Macintosh computer
and STELLA software for a weekend to Frank Draper, who teaches
8th grade biology. Draper came back on Monday to say, "This
is what I have always been looking for, I just did not know what
it could be."
At first Draper expected
to use computer simulation in one or two classes during a term.
Then he found that systems thinking and simulation were becoming
a part of every class. That led to concern that he would not have
time to cover all the biology subject if so much time was being
devoted to the system dynamics component. But two thirds of the
way through the term, Draper found he had completed all the usual
biology content. The more rapid pace had resulted from the way
biology had become more integrated and from the greater student
involvement resulting from the systems viewpoint. Also, much credit
goes to the "learner-directed learning" organization
of student cooperative study teams within the classroom that was
introduced at the same time. (19) To quote Draper, "There
is a free lunch."
- (19) See Forrester (1990) "System Dynamics as a Foundation
for Pre-College Education" for a more complete description
of the combination of systems thinking and learner-directed learning.
Whether we think of pre-college
or management education, the emphasis will focus on "generic
structures." A rather small number of relatively simple structures
appear repeatedly in different businesses, professions, and real-life
settings. One of Draper's junior high school students grew bacteria
in a culture dish, then looked at the same pattern of environmentally
limited growth through computer simulation. From the computer,
the student looked up and observed, "This is the world population
problem, isn't it?" Such transfer of insights from one setting
to another will help to break down the barriers between disciplines.
It means that learning in one field becomes applicable to other
There is now promise of
reversing the trend of the last century that has been moving away
from the "Renaissance man" idea toward fragmented specialization.
We can now move back toward an integrated, systemic, educational
process that is more efficient, more appropriate to a world of
increasing complexity, and more supportive of unity in life.
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1939 B. Sc. University of Nebraska, Electrical Engineering
1945 M. Sc. Massachusetts Institute of Technology, Electrical
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1954 University of Nebraska, Engineering
1969 Boston University, Science
1971 Newark College of Engineering, Engineering
1973 Union College, Science
1974 University of Notre Dame, Engineering
1979 University of Mannheim, Germany, Political Science
1988 State University of New York, Humane Letters
1990 University of Bergen, Norway, Philosophy
1998 University of Seville, Spain
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HONORS AND AWARDS
1962 Academy of Management Award for Industrial Dynamics
1967 National Academy of Engineering
1968 Inventor of the Year, George Washington University
1968 Fellow, American Academy of Arts and Sciences
1969 Valdemar Poulsen Gold Medal, Danish Academy of Technical
1969 Fellow, Academy of Management
1970 Member, Club of Rome
1970 Publications Award, for Urban Dynamics, Organization
1972 Medal of Honor, Institute of Electrical and Electronics Engineers
1972 System, Man, and Cybernetics Award for Outstanding Accomplishment,
Institute of Electrical and Electronics Engineers
1972 New England Award, The Engineering Societies of New England
1972 Benjamin Franklin Fellow, The Royal Society of Arts, London
1972 Appointed to the Germeshausen Professorship Chair, Massachusetts
Institute of Technology
1974 Howard N. Potts Medal, The Franklin Institute
1976 Honorary Member, Society of Manufacturing Engineers, in recognition
of the work of several at MIT in digital control of machine tools
1977 Harry Goode Memorial Award, American Federation of Information
1979 Inventors Hall of Fame
1979 The Common Wealth Award of Distinguished Service
1980 Fellow, American Association for the Advancement of Science
1982 Computer Pioneer Award, IEEE Computer Society
1986 Jay W. Forrester Chair in Computer Studies at MIT, endowed
by Thomas J. Watson, Jr.
1987 James R. Killian, Jr. Faculty Achievement Award, Massachusetts
Institute of Technology
1987 Honorary Professor, Shanghai Institute of Technology, China
1987 Forrester-Yang Reading Room for System Dynamics, Fudan University,
1987 Agricoltura 2000 Award, Rome, Italy
1988 Information Storage Award, IEEE Magnetics Society
1988 Lord Foundation Award
1989 U.S. National Medal of Technology (with Robert R. Everett)
1990 Pioneer Award, IEEE Aerospace and Electronic Systems Society
(with Robert R. Everett)
1998 Price Waterhouse Information Technology Leadership Award
for Lifetime Achievement
(Go to top.)
- Forrester, Jay W. 1975. Collected Papers of Jay W. Forrester.
Waltham, MA. Pegasus Communications. 284 pp.
- ----- 1971. World Dynamics. (2nd, 1973 ed.). Waltham,
MA. Pegasus Communications. 144 pp. Second edition has an added
chapter on physical vs. social limits.
----- 1969. Urban Dynamics. Waltham, MA. Pegasus Communications.
----- 1968. Principles of Systems. (2nd ed.). Waltham,
MA. Pegasus Communications. 391 pp.
----- 1961. Industrial Dynamics. Waltham, MA. Pegasus
Communications. 464 pp.
(Go to top.)
- Forrester, Jay W. forthcoming. Beyond Case Studies--Computer
Models in Management Education. In Peter Milling (ed.), A chapter
for a book in honor of Professor Gert von Kortzfleisch, Univ.
of Mannheim, Germany.
---- forthcoming. Low Productivity: Is It the Problem, or
Merely a Symptom? In William F. Christopher and Carl G. Thor
(ed.), Productivity Measurement Handbook. Portland, OR:
---- 1990. System Dynamics as a Foundation for Pre-College
Education. In George P. Richardson David F. Anderson and John
D. Sterman, ed., Volume 1: System Dynamics '90, pp. 367-380,
System Dynamics Society, Mime 300, Rockefeller College, University
at Albany--SUNY. Also available as Memo D 4133, System Dynamics
Group, Sloan School, Massachusetts Institute of Technology
---- 1989. A Economics Pilot Plant. CHEMTECH, Vol.
19, No. 1, American Chemical Society, pp. 26-33.
---- 1987. Nonlinearity in High-Order Models of Social Systems.
European Journal of Operational Research, Vol. 30, No.
2, pp. 104-109. From a conference on Modelling Complex Systems,
Prigogine Center, Uni. of Texas, March, 1985.
---- 1987. Lessons from System Dynamics Modeling. System
Dynamics Review, Vol. 3, No. 2, pp. 136-149.
---- 1987. The Economy: Where is it Headed? Los Angeles
Daily News. Los Angeles. October 25, 1987. Also available
as Report D-3937, System Dynamics Group, Sloan School of Management,
---- 1987. Fourteen "Obvious Truths". System
Dynamics Review, Vol. 3, No. 2, pp. 156-159. An archive reprinting
of parts of a 1960 paper, "The Impact of Feedback Control
Concepts on the Management Sciences," the full paper is
available as Chapter 3, pp. 45-60, in the author's Collected
Papers, 1975, Waltham, MA., Pegasus Communications
---- 1985. Economic Conditions Ahead: Understanding the Kondratieff
Wave. The Futurist, Vol. XIX, No. 3, pp. 16-20.
---- 1985. "The" Model Versus a Modeling "Process".
System Dynamics Review, Vol. 1, No. 1, pp. 133-134. An
archive reprinting from report D-1621, 1971, System Dynamics
Group, Sloan School of Management, MIT.
---- 1984. The System Dynamics National Model--Objectives,
Philosophy, and Status. In International System Dynamics Conference,
Oslo, Norway, August 2-5, 1984, pp. 1-16, 49 Bedford Road,
Lincoln, MA 01773 USA: System Dynamics Society. Also available
as Memo D-3570 from System Dynamics Group, Sloan School, MIT
---- 1983. Innovation and Economic Change. In Christopher
Freeman (ed.), Long Waves in the World Economy. pp. 126-134.
---- 1983. Conversation: Jay W. Forrester--Interviewed by
Christopher Evans. Annals of the History of Computing,
Vol. 5, No. 3, pp. 297-301.
---- 1982. Global Modelling Revisited. Futures, Vol.
14, No. 2, pp. 95-110. From a lecture at the IIASA Global Modelling
Conference, Laxenburg, Austria, Sept. 1981.
---- 1982. Education for the 21st Century. In Frank P. Davidson,
& C. Lawrence Meador (ed.), Macro-Engineering and the
Future: A Management Perspective. pp. 239-248. Boulder, CO:
---- 1981. Inflation and Unemployment. In E. Paulre, ed.,
System Dynamics and the Analysis of Change: Proceedings of
the 6th International Conference on System Dynamics, University
of Paris-Dauphine, November, 1980, pp. 111-135, New York:
----, and Peter M. Senge. 1980. Tests for Building Confidence
in System Dynamics Models. In A. A. Legasto Jr. et al (ed.),
System Dynamics. Series: TIMS Studies in the Management
Sciences. pp. 209-228. New York: North-Holland.
---- 1980. System Dynamics--Future Opportunities. In A. A.
Legasto Jr. et al (ed.), System Dynamics. Series: TIMS
Studies in the Management Sciences. pp. 7-21. New York: North-Holland.
---- 1980. Information Sources for Modeling the National Economy.
Journal of the American Statistical Association, Vol.
75, No. 371, pp. 555-574.
---- 1980. More Productivity Will Not Solve Our Problems.
Business and Society Review, Vol. Fall 1980, No. 35, pp.
---- 1979. A Self-Regulating Energy Policy. Astronautics
& Aeronautics, Vol. 17, No. 7/8, pp. 40-45 and 53.
---- 1979. An Alternative Approach to Economic Policy: Macrobehavior
from Microstructure. In Nake M. Kamrany and Richard H. Day (ed.),
Economic Issues of the Eighties. pp. 80-108. Baltimore:
Johns Hopkins University Press.
---- 1979. Innovation and the Economic Long Wave. Management
Review, Vol. 68, No. 6, Am. Management Assoc., pp. 16-24.
Also in The McKinsey Quarterly, Spring 1979, pp. 26-38;
and in The Best of Business, Vol 3, No. 1, Spring 1981,
---- 1979. Testimony: 'Excess' Profits Tax and Energy Policy.
In Hearings Before the Subcommittee on Energy and Foundations,
Senate Committee on Finance, May 11. pp. 239-251. Washington
DC: U.S. Government Printing Office.
---- 1978. Changing Economic Patterns. Technology Review,
Vol. 80, No. 8, pp. 47-53.
---- 1977. Growth Cycles. De Economist, Vol. 125, No.
4, pp. 525-543. H. E. Stenfert Kroese B. V., Leiden, The Netherlands
---- 1977. World Models: The System-Dynamics Approach. In
M. Marois, ed., Volume 4: Proceedings of the World Conference:
Towards a Plan of Actions for Mankind, pp. 107-112, Oxford:
---- 1977. New Perspectives on Economic Growth. In Dennis
L. Meadows (ed.), Alternatives to Growth--A Search for Sustainable
Futures. pp. 107-121. Cambridge, MA: Ballinger.
---- 1976. Comments on National Growth. In Harold M. Hochman
(ed.), The Urban Economy. pp. 137-15 1. New York: W. W.
Norton & Co.
---- 1976. Testimony on the Future of Growth and the Environment.
In Hearings, Panel on Environmental Science and Technology,
Subcommittee on Environmental Pollution, Committee on Public
Works, U. S. Senate, 94th Congress. pp. 3-95. Washington,
D.C.: U.S. Government Printing Office.
---- 1976. A New View of Business Cycles. The Journal of
Portfolio Management, Vol. 3, No. 1, pp. 22-32.
---- 1976. Overlooked Reasons for Our Social Troubles. In
Harold M. Hochman (ed.), The Urban Economy. pp. 158-163.
New York: W. W. Norton & Co.
---- 1976. Business Structure, Economic Cycles, and National
Policy: Reply. Business Economics, Vol. XI, No. 3, pp.
---- 1976. Moving into the 21st Century: Dilemmas and Strategies
for American Higher Education. Liberal Education, Vol.
LXII, No. 2, pp. 158-176.
---- 1976. Educational Implications of Responses to System
Dynamics Models. In C. West Churchman and Richard 0. Mason (ed.),
World Modeling: A Dialogue. pp. 27-35. Amsterdam: NorthHolland.
---- , N. J. Mass, and C. J. Ryan. 1976. The System Dynamics
National Model: Understanding Socioeconomic Behavior and Policy
Alternatives. Technological Forecasting and Social Change,
Vol. 9, No. 1/2, pp. 51-68.
---- 1976. The Validity of System Dynamics: An Interchange.
Technology Review, Vol. 78, No. 8, pp. 2-3, 72.
---- 1976. Business Structure, Economic Cycles and National
Policy. Business Economics, Vol. XI, No. 1, pp. 13-24.
Also in Futures, pp. 195-214, June 1976 and in Ralph Jones,
ed, Readings from Futures pp. 155-174, Guildford, England:
Westbury House, 1981.
---- 1976. Population vs. Standard of Living: The Trade-Off
That Nations Must Decide. The Futurist, Vol. X, No. 5,
pp. 246-250. Originally given as testimony for the Panel on Environmental
Science and Technology, Environmental Pollution Subcommittee,
Senate Committee on Public Works, February, 1976.
---- , and others. 1975. The Use of Data in Modeling: A Discussion.
In Walter W. Schroeder III, et al (ed.), Readings in Urban
Dynamics: Volume 2. Pp. 81-90. Waltham, MA. Pegasus Communications.
---- , and N. J. Mass. 1975. Urban Dynamics: A Rejoinder to
Averch and Levine. In Walter W. Schroeder III, et al (ed.), Readings
in Urban Dynamics: Volume 2. PP. 11-30. Waltham, MA. Pegasus
---- 1975. The Road to World Harmony. The Futurist,
Vol. IX, No. 5, pp. 231-234.
---- 1975. Limits to Growth Revisited. Journal of the Franklin
Institute, Vol. 300, No. 2, pp. 107-111.
---- 1975. Urban Goals and National Objectives. In Collected
Papers of Jay W. Forrester. Pp 245-253. Waltham, MA. Pegasus
Communications. Presented at the Conference on Cities, Indianapolis,
Ind., May 25-28, 1971.
---- 1975. The Impact of Feedback Control Concepts on the
Management Sciences. In Collected Papers of Jay W. Forrester.
pp. 45-60. Waltham, MA. Pegasus Communications Originally delivered
as the 1960 FIER Distinguished Lecture for the Foundation for
Instrumentation Education and Research.
---- 1975. Understanding Social and Economic Change in the
United States. Simulation, Vol. 24, No. 4 and 5, pp. 125-128
---- 1974. Toward a National Urban Consensus. In N. J. Mass
(ed.), Readings in Urban Dynamics: Volume 1. PP. 245-255.
Waltham, MA. Pegasus Communications. Also appears as Chapter
12, pp. 191 200, in the author's Collected Papers, 1975,
Waltham, MA. Pegasus Communications.
---- , N. J. Mass, and Gilbert W. Low. 1974. The Debate on
World Dynamics: A Response to Nordhaus. Policy Sciences,
Vol. 5, No. 2, pp. 169 190.
---- 1973. The Fledgling Cheermonger. Cambridge Review,
Vol. 94, No. 2211, pp. 70-73.
---- 1972. Should We Save Our Cities? Business and Society
Review, Vol. Spring 1972, No. 1, pp. 57-62.
---- 1972. Churches at the Transition Between Growth and World
Equilibrium. ZYGON, Vol. 7, No. 3, pp. 145-167. Also appears
as Chapter 16, pages 255-269, in the author's Collected Papers
1975; and Chapter 13, pages 337-353, in Toward Global Equilibrium,
1973, edited by Dennis L. Meadows, both from Waltham, MA. Pegasus
---- 1972. Control of Urban Growth. APWA Reporter,
Vol. 39, No. 10, pp. 14-19. Keynote address at the annual meeting
of the American Public Works Association. Also available as Chapter
17, pages 271-284, in the author's Collected Papers 1975;
and as Chapter 19, pp. 257-271, in Readings in Urban Dynamics:
Volume 1, 1974, N. J. Mass, ed., both from Waltham, MA. Pegasus
---- 1971. Testimony. In Hearings before the Ad Hoc Subcommittee
on Urban Growth of the Committee on Banking and Currency, House
of Representatives, Part 3, October 7, 1970. pp. 205-265.
Washington, D.C.: U.S. Government Printing Office.
---- 1971. Counterintuitive Behavior of Social Systems. Technology
Review, Vol. 73, No. 3, pp. 53-68. Also appears as Chapter
14, pages 211-244, in the author's Collected Papers 1975;
and as Chapter 1, pp. 3-30, in Toward Global Equilibrium:
Collected Papers, 1973, Dennis L. Meadows, ed., both from
Waltham, MA. Pegasus Communications.
---- 1970. Toward a National Urban Policy. Social Service
Outlook, Vol. 5, No. 6, pp. 6-7. A condensed version of "Toward
a National Urban Consensus" that appears in full as Chapter
12, pages 191-200, in the author's Collected Papers 1975;
also appears as Chapter 18, pp. 245255, in Readings in Urban
Dynamics: Volume 1, 1974, N. J. Mass, ed., both from Waltham,
MA. Pegasus Communications.
---- 1970. Growth, Equilibrium, and Self-Renewal. In Creative
Renewal in a Time of Crisis: Report of the Commission on MIT
Education. pp. 171-184. Cambridge, Mass.: Massachusetts Institute
of Technology. Also appears as Chapter 13, pages 201-210, in
the author's Collected Papers, 1975, Waltham, MA. Pegasus
---- 1969. Overlooked Reasons for Our Social Troubles. Fortune,
Vol. LXXX, No. 7, December, pp. 191-192.
---- 1969. Environment and Invention, IDEA, George Washington
University, Vol. 13, No. 2, pp. 279-283.
---- 1969. A Deeper Knowledge of Social Systems. Technology
Review, Vol. 71, No. 6, pp. 21-31.
---- 1969. Engineering Education and Practice in the year
2000. Engineering Education, Vol. 60, No. 10, pp. 974-979.
Also available in Futures, pp. 391-401, Sept. 1969.
---- 1969. Systems Analysis as a Tool for Urban Planning.
In Martin Goland (ed.), The Engineer and the City. pp.
44-53. Washington, D.C.: National Academy of Engineering. Reprinted
in several places, including Chapter 2 in Readings in Urban
Dynamics: Volume 1, 1974, N. J. Mass, ed, and as Chapter
11, pp. 175-189, in the author's Collected Papers, 1975,
both from Waltham, MA. Pegasus Communications; and in Industrialized
Building Systems for Housing, Albert G. H. Dietz and Laurence
S. Cutler, eds., MIT Press, Cambridge, MA, 1971.
---- 1968. Planning under the Dynamic Influences of Complex
Social Systems. In Erich Jantsch, ed., Perspectives of Planning:
Proceedings of the OECD Working Symposium on LongRange Forecasting
and Planning, Bellagio, Italy, October 27-November 2, 1968,
pp. 235254, Paris: Organization for Economic Cooperation and
Development. Also in Arts and the Environment, ed. Gyorgy
Kepes, George Braziller, NY, 1972. Excerpts appear as Chapter
10, pages 167-174, in the author's Collected Papers, 1975,
Waltham, MA. Pegasus Communications.
---- 1968. Industrial Dynamics--A Response to Ansoff and Slevin.
Management Science, Vol. 14, No. 9, pp. 601-618. Also
appears as Chapter 9, pages 151-165, in the author's Collected
Papers, 1975, Waltham, MA. Pegasus Communications.
---- 1968. Market Growth as Influenced by Capital Investment.
Industrial Management Review (MIT), Vol. 9, No. 2, pp.
83-105. Also appears as Chapter 7, pages 111-132, in the author's
Collected Papers 1975; and as Chapter 12, pp. 205-226,
in Edward B. Roberts, ed., Managerial Applications of System
Dynamics, 1978, both from Waltham, MA. Pegasus Communications.
---- 1968. Reflections on the Bellagio Conference. In Erich
Jantsch, ed., Perspectives of Planning: Proceedings of the
OECD Working Symposium on Long-Range Forecasting and Planning,
Bellagio, Italy, October 27-November 2, 1968, pp. 503-510,
Paris: Organization for Economic Cooperation and Development.
---- 1968. Industrial Dynamics--After the First Decade. Management
Science, Vol. 14, No. 7, pp. 398-415. Also appears as Chapter
8, pages 133-150, of the author's Collected Papers, 1975,
Waltham, MA. Pegasus Communications.
- ---- 1966. Modeling the Dynamic Processes of Corporate Growth.
In Proceedings of the IBM Scientific Computing Symposium on
Simulation Models and Gaming, December 7-9, 1964, pp. 23-42,
Yorktown Heights, NY: International Business Machines Corporation.
---- 1966. Social Structure and Motivation for Reducing Research
Costs. Research Management, Vol. 9, No. 1, pp. 45-60.
Also appears as Chapters, pages 81-92, in the author's Collected
Papers, 1975, Waltham, MA. Pegasus Communications.
---- 1965. A New Corporate Design. Industrial Management
Review (MIT), Vol. 7, No. 1, pp. 5-17. Also appears as Chapter
6, pages 93 109, in the author's Collected Papers, 1975,
Waltham, MA. Pegasus Communications.
---- 1965. Modeling of Market and Company Interactions. In
Peter D. Bennett, ed., Marketing and Economic Development:
The 50th Anniversary International Symposium of Marketing, Sept.
1-3, 1965, in Washington D.C., pp. 353-364, Chicago: American
Marketing Association. Reprinted as Chapter 5, pp. 99-111, R.
J. Lawrence and M. J. Thomas, ed., Modern Marketing Management,
Penguin Books, 1971.
---- 1965. The Structure Underlying Management Processes.
In Edwin B. Flippo, ed., 24th Annual Meeting of the Academy
of Management, Dec. 28-30, 1964, pp. 58-68, Chicago, IL:
Academy of Management.
---- 1965. Corporate Structure in the Age of Technological
Innovation. In Richard A. Beaumont, ed., Computer Technology--Concepts
for Management, May 7-8, 1964, pp. 61-77, Greenwich, Conn.:
Industrial Relations Counselors, NY.
---- 1964. Common Foundations Underlying Engineering and Management.
IEEE Spectrum, Vol. 1, No. 9, pp. 66-77. Also appears
as Chapter 4, pages 61-80, in the author's Collected Papers,
1975, Waltham, MA. Pegasus Communications.
---- 1964. A New Avenue to Management. Technology Review,
Vol. LXVI, No. 3, pp. 9-11. Describing an experimental undergraduate
systems program at MIT.
---- 1963. Simulative Approaches for Improving Knowledge of
Business Processes and Environments. In CIOS XIII International
Management Congress, pp. 234-238, New York: Council for International
Progress in Management.
---- 1963. New Academic Opportunities In Management Systems.
Journal of Engineering Education, Vol. 53, No. 10, pp.
766-771. Describes the experimental "Systems Program"
for undergraduates at MIT.
---- 1962. Management Science: Its Impact. Technology Review,
Vol. 64, No. 3, pp. 27-29, 36, and 38.
---- 1962. Managerial Decision Making. In Martin Greenberger
(ed.), Management and the Computer of the Future, pp.
36-91. Cambridge MA: MIT Press.
---- , William M. Pease, James 0. McDonough, and Alfred K.
Susskind. 1962. Numerical Control Servo-System, U.S. Patent
No. 3,069,608. Washington, D.C.: U.S. Patent Office, 37 pp.
Patent which launched the field of digital control of machine
---- 1959. Advertising: A Problem in Industrial Dynamics.
Harvard Business Review, Vol. 37, No. 2, pp. 100-110.
Also appears in revised form as Chapter 16 of the author's Industrial
Dynamics 1961, and as Chapter 2, pp. 31-44, in Collected
Papers 1975; and as Chapter 11, pp. 191-204, in Edward B.
Roberts, ed., Managerial Applications of System Dynamics,
1978, all from Waltham, MA. Pegasus Communications.
---- 1959. New Frontiers. In Eastern Joint Computer Conference,
December 3-5, 1958, pp. 5-10, New York: American Institute
of Electrical Engineers.
---- 1958. Industrial Dynamics--A Major Breakthrough for Decision
Makers. Harvard Business Review. Vol. 36, No. 4, pp. 37-66.
Also appears in revised form as Chapter 2 in the author's Industrial
Dynamics 1961; and Chapter 1, pp. 1-29, of Collected Papers
1975; also as Chapter 2, pp. 37-65 in Edward B. Roberts, ed.,
Managerial Applications of System Dynamics, 1978, all
from Waltham, MA. Pegasus Communications.
---- 1957. Systems Technology and Industrial Dynamics. In
Juan Cameron, ed., Adventure in Thought and Action--Fifth
Anniversary of the School of Industrial Management, MIT,
pp. 1021, Cambridge, MA: MIT Office of Publications. First paper
leading to the field of system dynamics.
---- 1956. Multicoordinate Digital Information Storage
Device, U.S. Patent No. 2,736,880. Washington, D.C.: U.S.
Patent Office, 11 pp. Patent for the memory system used during
the first 20 years of digital computers.
---- 1953. Coincident-Current Magnetic Computer Memory Developments
at M.I.T. In J. C. Chu, ed., Argonne National Laboratory Computer
Symposium, August 3-5, 1953, pp. 150-158, Lemont, IL: Argonne
---- 1952. Digital Computers: Present and Future Trends. In
Review of Electronic Digital Computers, Joint AIEE-IRE Computer
Conference, Philadelphia, December 10-12, 1951, pp. 109-113,
New York: American Institute of Electrical Engineers.
---- 1951. Digital Information Storage in Three Dimensions
Using Magnetic Cores. Journal of Applied Physics, Vol.
22, No. 1, pp. 44-48.
---- 1951. The Digital Computation Program at Massachusetts
Institute of Technology. In Second Symposium on Large-Scale
Digital Calculating Machinery, pp. 44-49, Cambridge, MA:
Harvard University Press.
---- 1948. High-Speed Electrostatic Storage. In Symposium
on Large Scale Digital Calculating Machinery, pp. 125-129,
Cambridge, MA: Harvard University Press.
Brown, Gordon S., and Jay W. Forrester. 1946. Remote Control
System, Patent No. 2,409,190. Washington, D.C.: U.S. Patent
Office, 10 pp.
(Go to top.)
SELECTED WORKING PAPERS
- ---- 1988. Designing Social and Managerial Systems
(D-4006-1). Cambridge, MA: System Dynamics Group, Sloan School
of Management, MIT. October 20, 1988. 10 pp. Award recipient
address, Lord Symposium, MIT.
---- 1987. Thoughts on Opportunities for the MIT School
of Management (D-3924-2). Cambridge, MA: System Dynamics
Group, Sloan School of Management, MIT. September 14, 1987. 5
---- 1987. Comparison of the 1920s and 1980s (D-3890).
Cambridge, MA: System Dynamics Group, Sloan School of Management,
MIT. April 8, 1987. 31 pp. Prepared for sponsors of the System
Dynamics National Model Project. -
---- 1985. Dynamic Modeling of the Arms Race (D-3684-3).
Cambridge, MA: System Dynamics Group, Sloan School of Management,
MIT. January 7, 1985. 6 pp.
---- 1985. System Dynamics in Management Education
(D-3721-1). Cambridge, MA: System Dynamics Group, Sloan School
of Management, MIT. June 3, 1985. 5 pp.
---- 1984. System Dynamics Modeling of the Arms Race
(D-3561). Cambridge, MA: System Dynamics Group, Sloan School
of Management, MIT. April 27, 1984. 9 pp. -
---- 1984. Comments on System Dynamics Modeling of Arms
Control (D 3544-1). Cambridge, MA: System Dynamics Group,
Sloan School of Management, MIT. March 11, l984.2pp.
- ---- 1984. Discussion Notes for Simple Arms Control Model
(D-3545). Cambridge, MA: System Dynamics Group, Sloan School
of Management, MIT. April 5, 1984. 16 pp.
---- 1983. Future Development of the System Dynamics Paradigm
(D 3454). Cambridge MA: System Dynamics Group, Sloan School,
Massachusetts Institute of Technology. July 27, 1983. 14 pp.
Keynote Address at the 1983 International System Dynamics Conference
---- 1979. Christianity in a Steady-State World (D-3171-1).
Cambridge, MA: System Dynamics Group, Sloan School, Massachusetts
Institute of Technology. December 9, 1979. 12 pp. Sunday sermon,
Parish of the Epiphany Episcopal, Winchester, MA.
(Go to top.)
Revised, March 13, 2000