Decompose tasks into steps before estimating — holistic…
When unpacking task estimates, decompose complex tasks into component steps before estimating duration—unpacking improves accuracy by forcing visibility of dependencies and transitions that holistic estimation skips.
When This Fires
- Estimating time for any task that takes more than 2 hours
- Sprint planning, project estimation, or deadline setting
- When someone asks "how long will this take?" and you feel confident in a single number
- Any estimation where the task is described in one sentence but involves multiple steps
Common Failure Mode
Decomposing into functional steps but forgetting transition costs. "Step 1: design (2h), Step 2: implement (4h), Step 3: test (2h) = 8 hours total." But this misses the context-switching time between steps, the setup costs within each step, and the rework when step 3 reveals problems in step 2. Add 20-30% for transitions, or decompose each step further until transitions become visible.
The Protocol
Before estimating any complex task: (1) List every component step — aim to decompose until each step takes less than 2 hours. (2) For each step, estimate independently. (3) Identify dependencies: which steps require outputs from other steps? (4) Add transition time between steps (typically 15-30 minutes each). (5) Sum the decomposed estimates. The total will almost always exceed your holistic estimate — and the decomposed version is almost always more accurate.