← Metrics Reference | Production Phase 2

Changeover Time

Time from the last good part of one production run to the first good part of the next — a key target for SMED and flexibility improvement.

Formula

Time of First Good Part (new run) − Time of Last Good Part (previous run)

Benchmarks

World-class: <10 minutes (SMED goal) Good: <30 minutes for complex changeovers Typical: 30–120 minutes Poor: >120 minutes or highly variable

What Is Changeover Time?

Changeover Time measures the complete transition between production runs — from the last good part of the previous run to the first good part of the next. It includes teardown, tooling changes, material changeover, startup, adjustment, and first article inspection.

Relationship to Setup Time: Changeover is the full end-to-end transition. Setup Time is a subset covering only the preparation and tooling phase. Changeover = teardown + setup + trial run and inspection.

The Formula

Changeover Time = Time of First Good Part (new run) − Time of Last Good Part (previous run)

What It Includes

  • Equipment shutdown and teardown
  • Tooling and fixture changes
  • Material changeover
  • Equipment startup
  • Adjustment and first article inspection

Benchmarks

LevelChangeover TimeNotes
SMED Goal<10 minutesSingle-Minute Exchange of Die
World-Class<30 minutesFor complex changeovers
Typical30–120 minutesVaries greatly by process
Poor>120 minutesOften indicates no standardised procedure

Data Requirements

SourceRequiredWhat You Need
Machine DataYesMachine state (changeover mode), product ID, quality status, timestamps

Changeover Time is a Phase 2 metric — it requires machine state tracking and product identification.

Why It Matters

  • Significant improvement opportunity — changeover time is often where the most production time is lost unnecessarily
  • Enables smaller batches — faster changeovers make it economical to run shorter production runs, improving flexibility and reducing inventory
  • Increases effective capacity — every minute saved on changeover is a minute of production gained
  • Tracks SMED effectiveness — measurable results from continuous improvement initiatives

Common Pitfalls

  • Not defining clear start and end points — “changeover started” is ambiguous
  • Including time waiting for the next job — this is scheduling delay, not changeover time
  • Not distinguishing internal from external changeover time — SMED depends on this distinction

SMED (Single-Minute Exchange of Die)

SMED is the methodology for reducing changeover time. The core idea is to separate changeover activities into:

  • Internal activities — can only be done while the machine is stopped (e.g. tool changes)
  • External activities — can be done while the machine is still running (e.g. preparing tools, staging materials)

The goal is to convert as many internal activities as possible to external ones, then streamline whatever internal activities remain.

Best Practices

  • Apply SMED methodology systematically — video record changeovers to identify every step
  • Track internal versus external time separately
  • Standardise changeover procedures so every operator follows the same sequence
  • Prepare materials and tooling in advance (external time) before stopping the machine
  • Celebrate changeover time reductions — they directly translate to increased capacity