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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.


  • Sandy Harlow

    Jay Forrester was a remarkable person, and the most inspiring teacher I ever had. I spent 4 years as a research and teaching assistant with the Systems Dynamics Group in the 1968-1972 period during which Jay wrote Urban Dynamics, World Dynamics, Principles of Systems, and testified before the US Congress on “The Counterintuitive Behavior of Social Systems”. I used his Urban Dynamics model to explore the impact of rent control on a city for my master’s thesis, and I was very fortunate to have Jay and former Boston mayor John Collins as my advisors. After I turned in the first draft of my thesis, Jay called and told me he didn’t think I would be able to graduate on time. When I asked why, he said I was trying to cover enough subjects in my thesis draft for 25 books, and it took me a few moments to realize that his feedback was not positive. We then talked about the appropriate balance between breadth and depth in a research project, and the fact that “a mile wide and an inch deep” might not be the appropriate dimension for an MIT thesis. His guidance was reflected in my next draft, and I was able to graduate on time. Jay believed in setting high standards for himself and others, and never changing them. I will always be grateful for the impact that this wonderful man had on my life.

  • Gokhan Dogan

    Jay was a great source of inspiration for many of us and he will continue to be with all his contributions. RIP…

  • Jeff Trailer

    Professor Forrester gave a lecture one day in our class and told us a personal story to emphasize his philosophy on the importance of high quality standards. He said he once visited a U.S. Navy ship that was installing an experimental radar device, of his design. The engineers were explaining to him how the device would be installed. Upon seeing the device and hearing the plan, he expressed to them his concern about the low quality of work in the construction of the device. The engineers quickly dismissed his concern, stating how they had worked very hard on the device and that it was in excellent working order. To their horror, he walked up to the device and with one hand broke off a flimsy part and then handed it to one of the engineers. He said, the sailors won’t be as gentle with it as I am. (I served in the Navy and so this was especially memorable for me). In 2003 I asked him about his book Industrial Dynamics. I asked, looking back on it now, would you change any of your conclusions? He was quiet for a moment, and said simply “no.” And then smiled.

  • Shamim Bodhanya

    Good Evening

    I just learned that Jay Forrester, the founder of System Dynamics passed away at the age of 98.

    Jay has had such a huge impact on the world, in ways that we cannot imagine. I have learned so much about systems and complexity through the wisdom of Jay’s work.

    His imprints on the work that my colleagues and I have done over the last 17 years in this field are indelible.

    I have learnt, and continue to learn the field of system dynamics and related systems and complexity field from the work of Jay, his students and colleagues, and from the resources from the various centres and institutions engaged in system dynamics.

    I ran a workshop on Systems Thinking for Executives over the last two days, much of which was inspired by the work of Jay and the broader system dynamics community.

    May the Lord accept Jay into His presence and mercy, may his soul rest in peace, and may his work continue to inspire us to create a better world for all.


    Shamim Bodhanya
    Durban, South Africa

  • Jay was a great educator. He did more toward opening my eyes to the way the world works than anyone else in my 17 years of education. As an undergrad at MIT from 1988-1993, the works in the field he created allowed me to learn Differential Equations through real world applications via computer simulations, far more meaningful than it would have been under common teaching practive. It so excited my desire to learn more that it led me to a few years with him in the System Dynamics in Education Project and in Sterman’s full SD courses. At the time, I was too young and clueless to be in awe of him. He gave us so much room to grow, while providing deep and thoughtful oversight of our work. He created an amazing opportunity for us undergraduate researchers to learn by doing, while truly making a contribution to K-12 education and beyond. He will be remembered as the most powerful force in my development into the person I am today. And I know that his impact has been far reaching beyond even what most people realize. With feedback loops and unintended consequences part of common parlance in the press 30 years later.

  • Marc Haddad

    Out of all my PhD studies at MIT, none of which were directly related to SD, the course that lit the brightest light bulb for me was Jay Forrester’s 15.874, this is where I learned to see life in dynamic terms. Thank you Prof. Forrester, the world is less smarter this evening, they’re lucky to have you on the other side, Godspeed.

  • Weishuang Qu

    Jay is a great pioneer and educator, and he is always a role model for me, and probably for many others.

  • Paul Newton

    Like many others I have several “Jay stories” that I could share, but the main thing I want to express here is my gratitude to Jay Forrester for system dynamics. It has changed my views on almost everything. Thank you Professor Forrester…

  • Erling Moxnes

    In 1979 I came to Dartmouth College with lots of questions in my mind about the working of social systems. Learning about SD I got more answers than I had questions. The clarity of Forrester’s writing made a great impression, and so did the many anecdotes about him. Jay had a strong influence on my life, and continues to influence our students’ lives.