What it corrects
Outcomes rewrite memory. After success, assumptions look obvious; after failure, warning signs look impossible to miss. A decision journal preserves what was believed when the outcome was still unknown, so experience can produce calibration instead of hindsight stories.
The journal is not a diary. It is a dated, testable record of a call.
How it works
- Record the decision, date, alternatives, and reasoning.
- Write the expected outcome and confidence precisely enough to revisit.
- List the assumptions that must hold.
- Set a review date or trigger.
- Compare outcome with prediction without editing the original entry.
In a Business Case Weekly case
Every decidenda answer is already the beginning of a journal entry. In the Nike case, improve it by adding the assumption that carries the recommendation, an observable tripwire, and when the decision should be reviewed.
In your answer
- “I decide to … because …”
- “This depends on …; I am least certain about …”
- “I will review the call when … and change course if …”
Common misuse
Do not grade a decision only by its outcome. Review whether the reasoning used the information available at the time, whether confidence was calibrated, and whether execution followed the intended plan.