---
name: capacity-planning
description: Use when asked to determine whether available capacity — production, staffing, or infrastructure — will meet projected demand, and what to do about a gap or a surplus in either direction, as distinct from [[demand-forecasting]], which produces the demand projection capacity planning is measured against rather than deciding what to do about it.
---

# Capacity Planning

Capacity planning is the practice of determining whether available
capacity — production lines, staffing, infrastructure — will meet
projected demand, and deciding what to do when it won't, or when
there's more capacity than needed. It turns a demand number into a
concrete decision about hiring, adding a shift, adding infrastructure,
or accepting a longer lead time.

## Key components

- **A demand projection as the input** — see [[demand-forecasting]] for
  how this is produced; capacity planning takes that projection as a
  given and asks whether current capacity can meet it.
- **Current capacity measured realistically** — actual usable output
  given maintenance windows, ramp-up time for new staff or equipment,
  and a realistic utilization rate, not the theoretical maximum the
  equipment or headcount could produce running flat-out with zero
  friction.
- **A plan for the gap in either direction** — for a shortfall: hire, add
  a shift, add infrastructure, or deliberately accept a longer lead
  time. For a surplus: a plan to use, reduce, or redeploy the excess
  rather than letting it sit idle.
- **Lead time to add capacity, factored into the decision date** — hiring,
  training, or installing new infrastructure all take time; the
  decision to add capacity has to be made that far ahead of when it's
  actually needed, not when the shortfall is already showing up.

## Why theoretical maximum overstates real capacity

A production line's rated output, or a team's headcount times standard
hours, describes a ceiling that's never actually sustained. Scheduled
maintenance, unplanned downtime, new hires ramping up to full
productivity, and a realistic (not 100%) utilization rate all reduce
what's actually usable below that theoretical number. Planning against
the theoretical maximum instead of the realistic one is one of the most
common ways a capacity plan looks adequate on paper and falls short in
practice.

## Common pitfalls

- **Planned against a single demand estimate** — sizing capacity to one
  point forecast with no scenario range means the plan is wrong the
  moment actual demand lands anywhere else on the range; see
  [[demand-forecasting]] for why a forecast needs an error range in the
  first place.
- **Capacity decisions made too late** — waiting until the shortfall is
  visible to decide to hire or add infrastructure ignores the lead time
  those actions actually take, so the added capacity arrives after the
  gap has already cost sales or service quality.
- **Surplus treated as free** — idle capacity still costs money (lease
  payments, depreciation, salaried staff with no work) even when it
  isn't causing visible problems; a surplus needs its own decision, not
  just relief that there's no shortage.
- **Theoretical maximum used as the baseline** — ignoring maintenance
  time, ramp-up curves, and realistic utilization overstates what's
  actually available and hides a gap until it's already being felt.
- **No plan for the direction not currently happening** — a plan built
  only for a shortfall has nothing to say when demand comes in lower
  than expected and leaves capacity sitting unused, and vice versa.

## Learn more

- [[demand-forecasting]] for the demand projection capacity is measured
  against, including why it needs a range rather than a single number.
- [[inventory-management]] for the related but distinct question of how
  much stock (rather than capacity) to hold against demand.
- [[logistics-planning]] for making sure the capacity to move goods
  keeps pace with the capacity to produce them.
- [[supply-chain-risk-assessment]] for identifying capacity that depends
  on a single supplier, site, or route with no fallback.