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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.


  • Although I never met Jay Forrester personally, I have been influenced a lot by his work. I first learned about his work in 1998 especially through Dennis Meadows and Richiro Oda. I also learned from his writings which were available online. Since then, I have used Jay’s special style of feedback-based systems thinking a lot in my facilitation work. In the first fifteen years of my career, I have been using it for facilitating transformational change, mainly in organization and development policy in my country, Indonesia. For the last two years, I am also applying his approach to systems thinking in different areas. Less on policy and organizational management, but more with children and organic gardening. In my facilitation work I often mentioned Jay as an example of a very inspirational change agent. Despite his age, he had endlessly worked toward a better future through his circle of influence. I would like to express my gratitude for the chance to learn from him important skills and knowledge that can transform so many people. Jay was one of the most important people who made skills and knowledge available for the world. For Jay, I send my deepest thanks.

  • David harold Chester

    Jay’s book on “World Dynamics” certainly got me thinking about how we may better represent our complete single country social macroeconomics as a system. The word System being the most significant here.

    It certainly can be and I find that the only sensible way to really know how about it works is by means of its representation using a model of the system and then finding the relationship between its various parts.

    My way of doing this may be seen in SSRN 2600103, which describes the model in terms of a way of its use for teaching. My book also helps which is mentioned in the references in this informal paper.

  • hummaira jabeen

    System dynamics has been a life changing subject for me, because of this subject I got job. Its been more than 6 years with system dynamics and still it keeps on astonishing me with its applications. Thanks Jay for this remarkable subject. Your work will be remembered always.
    May your soul rest in peace.

  • Lou Alfeld

    Jay. So many memories. Mentor, Teacher, Leader. The most influential person in my life. Jay taught us all, not only the importance of systems thinking, but also how to communicate those complex and innovative ideas. Thank you, Jay, for your patience and for your dedication. We all benefited enormously. You will never be forgotten.

  • I remember quite vividly the days in June 2007, while attending a workshop on system dynamics at MIT (led by John Sterman and Nelson Repenning).

    It was on Day 3, June 20, 2007, at 8:30 in the morning when Jay entered the room (age 88 at that time) and ran a session for 90 minutes straight. I was impressed by his appearance and how he got the attention of the room full of consultants, managers, and newbies to the field (like me who just had gotten pulled into the field a year earlier by John Sterman when I had been looking for ways to understand better the complex dynamics in a car plant where I worked back then in order to effectively intervene to improve the processes).

    During the following coffee break, Jay was standing a bit aside from the tables eating cake and sipping coffee. Nobody seemed to dare to get in touch with him. So I took the chance and approached, asking him whether I could ask him a question. “Sure!” he answered in a tone that made you feel that you both were on the same level.

    This moment in life had a major implication for me,

  • J. Pedro Mendes

    I wasn’t aware of his role back then when I programmed core-memory computers. I wasn’t aware either of the depth of his contribution when I first stumbled on “Industrial Dynamics”. Finally I had a chance to tell Jay in person about my appreciation for his work. “You should say that to my wife”, he replied.

  • Bryan Snyder (Prof.)

    I met Jay a few years back at Newbury Court where my wife Jill Crowley works as an Activities Director. I gave a talk on “Current Issues in Economics” and was delighted to discover one particular resident with a very sharp mind and a dry, yet pervasive sense of humor. We hit it off immediately. I had no idea who this chap was other than rumors of an MIT connection but shared his assessment of the current state of the Economics profession. Jay…was eminently practical in thought and application. My profession is neither. It was delightful to “talk shop” with Jay and amusing to find ourselves so close to the the same place as to our assessment of “Modern Economics”….coming from such different academic perspectives.

    I like Jay.

  • I met Jay Forrester two times, in 2008 and 2012, during the making of my documentary Last Call, which tells the story of The Limits to Growth. He was extremely helpful and it was an honor for me to have the opportunity to witness his genius.

  • Cuando conocí la dinámica de sistemas fue sorprendente ver como podía entenderse el mundo científicamente gracias a jay forrester por su labor académica. Cumpliò su tarea en este mundo.
    Una lastima su partida. Seguiré haciendo esfuerzos por difundir la dinámica de sistemas y el pensar en los sistemas.

    samuel prieto
    universidad del magdalena
    santa marta – colombia

  • As a bachelor student, I read Industrial Dynamics. The insights therein inspired me to pursue a career in Supply Chain Management, academics and simulation optimization. Unfortunately, I never got the chance to meet or listen live to a speech of Jay, but I am truly thankful to him for enabling me and my colleagues the world round to investigate complex questions with System Dynamics.