Decisions Without Rationale Become Traps

A decision on its own is weak memory. “We stopped broad match.” “We moved platforms.” “We changed attribution.” “We paused the campaign.” Useful, yes. But incomplete. Without the context and rationale, the next team cannot tell whether the decision was permanent, temporary, forced by a constraint, made under uncertainty, or simply the least bad option at the time.

Engineering teams have understood this problem for years. Architecture Decision Records exist specifically to preserve not just the choice, but the context, alternatives, trade-offs and consequences behind it. Microsoft’s guidance is explicit: a decision record without justification loses value over time because future teams cannot judge whether the original reasoning still applies. Microsoft Learn

A decision without its rationale is a rule with no expiry date.

That is how old decisions turn into organisational folklore. People inherit a practice, assume it was deliberate, and continue it long after the original constraint has disappeared. The better record is not “we did X.” It is “we did X because Y, under condition Z, and this was the result.” That small difference turns a historical note into something future teams can actually evaluate.

Decisions Without Rationale Become Traps

Further Reading