Fits

Evaluate whether the whole configuration actually improved on function, interfaces, total gain, and sustainability.

Six months ago your family adopted an elaborate shared system: a calendar app, a chore chart, automated reminders. Everyone still uses it, so it feels like a success. But your spouse spends Sunday evenings entering data, the reminders get swiped away unread, and the one person who resolves every conflict is more burdened than before the system existed. Nobody has ever actually asked whether the whole thing made life better.

FITS is the evaluation gate you run after real use, with four questions. Functional fit: did each part produce its required result at acceptable quality and reliability? Interface integrity: did meaning, responsibility, and exceptions survive the transfers between people and tools, or do things still fall in the cracks? Total-system gain: did the capability gained exceed the full cost, coordination, verification, maintenance, failures, not just the visible time saved? Safe and sustainable trajectory: did agency, learning, dignity, and resilience stay acceptable or improve for everyone, including the Sunday data-enterer? The cue is any adopted system that has run long enough to judge, which most never get. Run the four questions honestly, then reroute, simplify, or delete pieces whose overhead exceeds contribution. What changes is that you keep systems because they work, not because you built them. Avoid running FITS too early, before real use has generated evidence.