A schema unreviewed for 6 months is like an unupdated…

Treat any schema that has gone six months without deliberate review the same as a software dependency unupdated for six months - not necessarily broken but requiring verification before continued reliance.

When This Fires

During periodic schema portfolio reviews
Before making a consequential decision based on a schema you haven't reviewed recently
When you realize you've been operating on autopilot beliefs without examining them
During any "when did I last actually check this assumption?" moment

Common Failure Mode

Assuming that a schema's continued operation means it's still valid: "I've been using this approach for two years and it seems to work." But "seems to work" is a low-resolution assessment. The schema might be producing 70% quality when it used to produce 95% — a degradation invisible without deliberate review because you adapted to the lower quality gradually.

The Protocol

During schema portfolio review: (1) For each important schema, check: when was it last deliberately reviewed? (Not "when did I last use it" — when did I last examine whether it's still accurate?) (2) Any schema unreviewed for 6+ months → flag for verification. (3) Verification: does the schema still predict accurately? Have its assumptions changed? Has the environment shifted? (4) If verified → update the "last reviewed" date. If verification reveals drift → revise the schema. The verification itself takes 5-10 minutes per schema and prevents the slow accumulation of stale beliefs.