Please leave your comments

Jay Wright Forrester – founder of our field, leader, mentor, guide, and friend – 1918-2016. Born on Bastille Day, “but to my knowledge,” he once said recently, “the French haven’t taken any notice of it yet.” The System Dynamics community has had him in its midst since the late 1950s. We’ve heard his exhortations (and occasional scoldings) over these almost-60 years, and have grown as individuals and as a field from the examples he set for us. In the early years he struck fear in our hearts as we tried to meet his demands. In the later years we realized the warmth that lay under his drive for our perfection, and we are grateful for all of it.

Jay’s quotes are endlessly instructive. He was always challenging: “The solutions to small problems yield small results. … The most important problems are but little more difficult to handle than the unimportant.” He startled us: “The most important decision of the CEO is how to limit growth.” He saw a similar phenomenon in global dynamics: “Relying on technology to solve the problems created by growth is to evade the question of how to slow growth.” He insisted on an endogenous view: “We cause our own problems.” He always sought wise generalizations from his own model-based work: “Even if we manage to find a high leverage point in a complex system, we’re very likely to push the lever in the wrong direction.” He sought to improve practice in management science: “It’s false to assume that accuracy must be achieved before precision is useful.” In his enthusiasm he occasionally overreached: “Only System Dynamics modelers can talk for an hour without contradicting themselves.” (Just recently he moderated that: “Well, maybe twenty minutes.”) He had unwavering, quiet confidence, and urged us to have it too: “Have courage…”

Many of us have memories we cherish and want to share about Jay. This page is for us all. Write what you want others to see and hear. We will all gain from our memories of Jay.


  • I will always be grateful to Professor Jay Forrester for everything he taught me to appreciate in the world of System Dynamics through MIT’s Guided Study Program in System Dynamics.
    He showed a humbleness, kindness, and wisdom that I’ve rarely seen in anyone else and it was a great honor to have known, met, and be taught by him.
    Hopefully, his wisdom will continue to live on in all of us who were touched by him.

  • Professor, Jay W. Forrester I never meet you in person but I have known you by your works through your publications. I believe you are a father of system dynamics and recognize you as a pioneer in the field. I heard this sorrow in this morning and my heart felt break by losing you in the arena. I hope you have millions of stars you created in the world so that they can preach your work till the end of their life. Dear professor, I wish God will have mercy in you sole and promised to be dedicated to your work on system dynamics and I will flourish the ideas you invented.

  • John Richardson

    Those who came in contact with Jay may recall memorable episodes that capture some facet of his distinctive personality. One of my favorites is from a conference in Paris addressing global sustainability issues, held in the mid 1970s. Following Jay’s vigorous defense of the World3 model, a perennial, eminent critic posed commonly expressed reservations of the management science/operations research community having to do with the absence of “statistical validity” testing of World3. Jay responded. “There are many ways of establishing confidence in model results. Yes, one is statistical testing, as you say. However there is another test that I have found even more valuable. It is the validation of senior policy-makers who are so confident in a model’s results that they wish to put its lessons to use.” Jay continued: “I would like to discuss this further, however I must leave you. I have a scheduled meeting with President Guiscard D’Estaing to discuses these issues.” Jay gathered his things and departed the meeting room.

  • Imrana Umar

    Jay was certainly blessed with a long, prosperous and fulfilling life. His life-long achievements touched and shaped the lives of many people. My first encounter with Jay was in 1989 in University of Bergen where I was a graduate student of Information and Computer Science. Jay came and spoke about the field of System Dynamics for 16 hours over 2 days, covering a semester’s work, and I was sold. Since then, SD has been an elaborate part of my life.

    My last intimate encounter with Jay was in 2011 when I was fortunate to be the host co-chair of the SD conference in Washington DC. We spent an hour alone together when I took him to the Union station to catch a train back to Boston.

    May God give the family he left behind the heart to bear the loss. May we also, in the SD community, have the fortitude to continue to celebrate his life’s achievements!

  • Dr. Forrester showed me how Electrical Engineering approaches can contribute to the understanding of social problems. For mi, an Electronic Engineer from South America, this was a link between engineering and human issues. It gave me more motivation to study deeply the mathematic of circuits and systems. Dr. Forrester make us, the Engineers, better people and able to analyze the social responsibilities of our work.

  • Erne Nazira Bazin

    I’ve never met Jay Forrester in person but his articles has changed the way i think and my perspective not only in doing research but in every decision I made. Deep condolonces for this great loss.

  • Geoff Dean

    I first learned about system dynamics when I was an MIT student; I didn’t think that the recommendation in Forrester’s Urban Dynamics, that cities shouldn’t build subsidized housing, would have been a good thing for the kids I was tutoring in the housing projects behind MIT. But otherwise, the book was very interesting. Then in the early ’70s, when I taught at a college in Newark, I was hooked by his Counterintuitive Behavior article and then by Limits to Growth – I’ve followed his and his colleague’s work ever since. I was privileged to meet Jay at a Creative Learning Exchange conference a few years back, and what a delight that was. I wish the field was more widely taught in our post-secondary systems, and that more people knew how to “think in systems”; wish I’d been able to make more of that happen. But I have no doubt that Jay’s important influence will continue – and thanks to the System Dynamics Society for helping ensure that!

  • Tsuey-Ping Lee

    I met Jay when I was a doctoral student attending SD conference. Seeing him surrounded by many people, I was like a little fan hoping to shake hands with a superstar. It took me courage to go toward him and asked if I can get a handshake with him. He smiled warmly and extended his hand. I still remember how I don’t want to wash my right hand wishing to keep more “luck” with my modeling work. Although it happened decades ago, I still remember how I feel at that wonderful moment. Dear Professor Forrester, thank you so so much for your smile and kindness.

  • Donald kawal

    Jay visited the Iowa State campus around 1968. I was a PhD candidate at that time. His lectures were very informative and entertaining. I was taking an Industrial Dynamics class and had a copy of the ID book. I previously studied analytical systems theory which I was trying to adopt to management models.

    I was convinced to use Industrial Dynamics in my thesis which related to financial planning for a construction firm. Creating the model gave me significant exposure to the feedback loops in management decision making. Over time I became President of a construction company. The concepts were valuable.
    Recently I became aware of Systems Dynamics including applications to elementary school education. Jay has influenced many.

  • System Dynamics Society: Many of us have memories we cherish and want to share about Jay. This page is for us all. Write what you want others to see and hear. We will all gain from our memories of Jay.

    Jay Forrester’s ‘World Dynamics’ in 1971 is the inspiration for the current system dynamics research on the U. S. Constitution that is described in a recently published book series called ‘Chronicles of the Kwedake Dikep, a TimeLine of the Indian Spring on the Hill, TL of 2014’. The Hill is Capitol Hill and Jay Forrester’s original methodology for mapping dynamic social and urban systems is described in them as the bases for defining the Constitution by its six non-linear domain sets; Justice, Tranquility, Common Defense, General Welfare, Liberty and our Posterity.

    In the lectures concerning ‘World Dynamics’ Jay Forrester made in the early 1970s triggered a life -long curiosity about human systems and led to the Chronicles of the Kwedake Dikep in recent years as an ‘in situ’ examination of how to modify the Constitution to make genetic protections of life creation a human right. With CRISPR activity all over the world, the protections are not as easily incorporated into the Constitution as originally thought.

    I will be eternally grateful for his inspiration and that of the Sloan School methodology while I was at MIT’s Green Building and Plasma Fusion Center. Peace be with him.