Sprint Buffer Strategies - How Much Capacity to Reserve?
Our team keeps failing sprint commitments because production issues and urgent bugs eat into our planned work. Should we formally reserve buffer time in sprint planning? If so, how much - 10%, 20%, 30%? How do other teams handle this?
20% buffer works for most mature products. Calculate team capacity as velocity minus 20%. If your velocity is 50 points, plan for 40 points of committed work.
Critical: Track what fills the buffer. If it's consistently bugs, you have a quality problem. If it's production issues, improve monitoring. The buffer reveals systemic issues. After 3 months of tracking, you'll know your real sustainable pace.
We reserve 30% for on-call rotation. Each dev has one week per month on-call. During that week, we only commit them for 40% capacity. The other 60% is buffer for incidents.
Works beautifully - sprint commitments are finally predictable. On quiet on-call weeks, the dev knocks out tech debt or helps teammates. On fire-drill weeks, we still hit our sprint goal.
Controversial take: Don't reserve explicit buffer - it becomes a self-fulfilling prophecy. Instead, track interrupt-driven work as separate stories with estimates.
Make the cost visible. When stakeholders see "12 points of planned work delayed by 8 points of interrupts" sprint after sprint, they prioritize fixing root causes instead of accepting chaos as normal.
We use dynamic buffer based on sprint goal risk. High-risk sprint (new technology, external dependencies, regulatory deadline) = 30% buffer. Low-risk sprint (well-understood work, stable codebase) = 10% buffer.
Product owner chooses risk tolerance during planning. It's a business decision - sometimes we need predictability, sometimes we need maximum throughput.
We stopped calling it "buffer" and started calling it "sustainability capacity." Framing matters. Buffer sounds like waste. Sustainability capacity sounds like responsible planning. Management stopped questioning it immediately.