Keep commitments at 70-85% of capacity — the 15-30% slack…
Maintain commitment-to-capacity ratio between 0.70 and 0.85 to preserve system stability, keeping 15-30% of capacity uncommitted as structural buffer for variance absorption.
When This Fires
- Planning sprints, weeks, or project timelines
- Deciding how much to commit to in the next period
- When your schedule is "fully booked" and everything feels urgent and late
- After a period of chronic over-commitment that produced stress and missed deadlines
Common Failure Mode
Committing to 100% because "I should be able to do this much." The plan looks reasonable on paper because each individual task estimate seems accurate. But the plan has zero margin for the cumulative effect of many small variances — and in knowledge work, every estimate is uncertain. A plan at 100% utilization is a plan that requires everything to go exactly right. Nothing does.
The Protocol
When planning a week or sprint: (1) Estimate the total hours available (realistic, accounting for meetings, breaks, and admin). (2) Multiply by 0.70-0.85 to get your commitment budget. (3) Fill the commitment budget with prioritized work. Stop at the budget limit even if more work exists. (4) The remaining 15-30% stays uncommitted — it will absorb overruns, unplanned work, and energy fluctuations. (5) Track your actual utilization over time. If the slack is consistently consumed, you're underestimating task duration. If it's consistently unused, you can tighten the ratio toward 0.85.