What is POSIWID (The Purpose of a System Is What It Does)?

POSIWID, short for 'The Purpose Of a System Is What It Does,' is a systems thinking heuristic coined by Stafford Beer that judges a system by its actual behavior and outcomes rather than by its stated mission or intentions. If a system reliably produces a certain result, that result should be treated as its real purpose.

POSIWID is a useful, if uncomfortable, diagnostic for leaders: when an organization's outcomes consistently diverge from its mission statement, POSIWID suggests looking at the incentives, feedback loops, and structures actually in place, since those, not the stated values, are what is truly driving behavior.