Mixed Blessings: Valedictory Thoughts on System Dynamics Practice

ABSTRACT Some of the greatest developments in our field contain Mixed Blessings: positives and negatives, good stuff and bad stuff, brilliant aspects and actual flaws. In this paper I will call them ‘Blessings’ and ‘Bugs’. The Blessings help us do our strongest work, increase our skills, develop our insights, and expand our reach. But sometimes Blessings can turn into Bugs. They can get in our way by appearing to be indispensable, by insisting on being used, by substituting seductive simplicity for necessary deep thinking, by distracting us away from what really is going on, by cluttering our reports when they do not apply, by confusing our audiences when something else would work better. And when they are actually, subtly, wrong. This note offers reflections on the Blessings and Bugs in system dynamics practice as I have seen them, with the goal of strengthening and sharpening our field.