Changeover Time / Setup Time
Changeover time is the duration from the last good part of the previous product to the first good part of the next product. It directly impacts batch sizes, flexibility, and OEE.
Changeover time (also called setup time) includes everything that happens between producing the last good piece of Product A and the first good piece of Product B: Stopping the machine, removing tools, cleaning, installing new tools, adjusting settings, running test pieces, and quality verification.
Long changeover times force large batch sizes: If setup takes 4 hours, producing a small batch of 50 pieces makes no economic sense. This leads to overproduction, high inventory, and long lead times -- the cascade of waste triggered by setup inefficiency.
Changeover time is a key component of OEE's availability factor. Every minute of setup is a minute of lost production. Reducing changeover time directly increases effective capacity without capital investment.
The SMED methodology specifically targets changeover time reduction. But even without formal SMED, simply measuring and tracking changeover times creates visibility that drives improvement. What gets measured gets managed.
Formula
Changeover Time = Time of last good part (Product A) to first good part (Product B)
Practical Example
A printing press has a 75-minute changeover between jobs. With 8 changeovers per week, that is 10 hours of lost production -- more than an entire shift. After tracking each changeover step and applying SMED principles, changeover drops to 25 minutes. The freed 6.7 hours per week equal a 17% capacity increase.
How Leanshift Helps
Leanshift precisely timestamps every phase of the changeover process. By breaking setup into individual steps with measured times, teams can identify the longest steps and apply SMED to cut changeover time systematically.
Frequently Asked Questions
What is included in changeover time?
Everything from the last good part of the old product to the first good part of the new product. This includes shutdown, cleaning, tool change, adjustment, test runs, and quality approval. Many companies undercount by excluding test runs.
Why does changeover time affect batch size?
Long changeovers make small batches uneconomical because the setup cost is spread over fewer parts. Reducing changeover time makes small batches viable, enabling mixed-model production and shorter lead times.
What is a good changeover time?
It depends on the process, but SMED targets single-digit minutes (under 10 minutes). World-class operations achieve changeovers in 1-3 minutes. The benchmark is: short enough that batch size is no longer driven by setup time.
Related Terms
OEE (Overall Equipment Effectiveness)
OEE is the key metric for machine and equipment productivity. It combines availability, performance, and quality into a single percentage value.
SMED (Single Minute Exchange of Die)
SMED is a method for drastically reducing setup times. Goal: Every changeover in under 10 minutes -- in the single-digit minute range.
Heijunka (Production Leveling)
Heijunka smooths production volume and mix over time to eliminate peaks and valleys. It creates a steady, predictable flow that reduces waste and stress throughout the value stream.