capacity-planning

name	capacity-planning
description	Model team capacity across quarters, accounting for hiring, attrition, and project work. Use when forecasting resource availability for roadmaps.

Capacity Planning

Project realistic team capacity across multiple quarters to set achievable roadmaps and hiring needs.

Context

You are helping a tech lead forecast capacity for the next 2-4 quarters. If you have team size, hiring plans, or attrition history, use that data to ground the model.

Domain Context

• Larson's "An Elegant Puzzle" emphasizes team size as the primary lever for capacity change
• Reilly's "The Staff Engineer's Path": capacity planning must account for ramp time (new hires are 40-60% productive for 2-3 months)
• Research on team velocity: adding headcount doesn't linearly increase output due to communication overhead (Brooks' Law)

Key principles:

1. Headcount is destiny: Team capacity is determined almost entirely by team size, not optimization magic
2. New hires carry ramp cost: Budget 2-3 months at 40-60% productivity per new person, plus mentoring load on existing team
3. Attrition is normal: Plan for 10-15% annual attrition; losing a senior person costs ~3 months of productivity across team knowledge loss

Instructions

1. Baseline current capacity: Calculate your team's proven velocity (stories/points per sprint, or features per quarter). If new, estimate conservatively: 40 stories/quarter for a 6-person team
2. Model quarterly scenarios: Build three columns: headcount at quarter start, expected headcount at end (after hiring/attrition), and estimated velocity
3. Account for ramp time: For each new hire, reduce team velocity by 1-2 person-weeks for the month they start, plus 0.5 person-weeks for mentoring
4. Model attrition risk: If you lose a senior engineer, mark that quarter as -20% velocity. If you lose a mid-level engineer, -10%
5. Add contingency: Historical data shows 15-20% of plans get disrupted by incidents, support, or surprise work. Plan for 80-85% of theoretical capacity as available
6. Map to roadmap items: Take your roadmap (from technical-roadmap skill) and assign effort estimates. Does it fit in the available capacity windows? If not, prioritize or extend timeline
7. Make staffing cases: Identify roadmap items that require hiring to complete. Build business cases for each hire ("shipping feature X requires 2 more backend engineers in Q2")

Anti-Patterns

• Ignoring ramp time: LLMs often assume new hires contribute immediately. Reality: junior engineers are 30% productive for 3 months, mid-level 60% productive for 2 months. Always deduct.
• Confusing team size with team output: Adding 1 person doesn't add 20% capacity; communication overhead usually limits gains to 10-15%. LLMs often assume linear scaling.
• Planning without attrition: Most capacity plans ignore the 10-15% annual attrition rate. If your team has 5 people, plan for losing ~1 person per year.
• Forgetting mentoring load: When you hire, the team's productivity drops because senior people spend time onboarding. LLMs often plan as if mentoring is free.

Further Reading

• Larson, Will. "An Elegant Puzzle." Chapter on hiring and capacity.
• Brooks, Frederick. "The Mythical Man-Month." Addison-Wesley, 1975. Chapter on communication overhead.
• Reilly, Tanya. "The Staff Engineer's Path." Chapters on hiring and team composition.