How can changeover time be reduced in manufacturing?

Changeovers are one of the most underestimated areas of loss in manufacturing. They are planned. They are visible in the schedule. They are often not counted as a "stop". But a changeover where the machine is idle for three hours is three hours of unused capacity, regardless of whether the stop was planned or not.

For many factories, changeover time is the single greatest lever to increase capacity, meet varying demand, and improve OEE. And it is an area where improvements can often occur without major investments. It is about method, measurement, and sustained effort.

This guide covers how to reduce changeover times based on the SMED methodology, what is required for the change to stick, and why measurement is crucial from day one. Throughout, we assume that reducing changeover work is a continuous improvement process. A platform that visualizes the losses allows the work to be driven systematically over time, rather than as a one-off project that loses momentum after six months.

Why is changeover time a strategic issue?

Changeover time is strategic because it determines three things for a factory or production manager: capacity on the same machinery, flexibility towards customer demand, and competitiveness in a market with varying volumes.

Capacity on the same machinery. Every hour spent in changeover is an hour not producing. Halving the changeover times on a machine that is changed over five times a week, from four hours to two, yields ten extra production hours per week. Per year, this amounts to 500 hours, which represents a significant portion of a line's total capacity.

Flexibility towards customer demand. Long changeover times force long production runs. Long runs tie up capital in inventory, make the factory sensitive to changing customer requirements, and degrade delivery precision. Shorter changeovers do the opposite: you can run smaller batches, deliver more frequently, and hold fewer finished products in stock.

Competitiveness in a market with varying volumes. When demand changes rapidly, the factory that can adapt quickly wins. While competitors with longer changeover times hesitate, you have already started producing the new article.

This strategic perspective means that changeover work should not be treated as a minor operational exercise. It is a management decision that affects how the factory can act in the market.

What is SMED and how does the methodology work?

SMED stands for Single-Minute Exchange of Die and is a method for shortening changeover times in three steps: separate internal and external setup, convert internal elements to external, and streamline the remaining tasks. The term was coined by Shigeo Shingo in Japan during the 1950s and 60s, and the original ambition was to be able to change over tools in under ten minutes. The methodology has since become a cornerstone of lean and has been used successfully in all types of manufacturing, from the automotive industry to food production.

SMED is built on three steps.

Step 1: Separate internal and external setup

The first, and often the biggest, step is about classifying every element in the changeover.

Internal setup includes work that can only be performed when the machine is completely stationary. This applies, for example, to tool changes, adjustments inside the machine, or other tasks that require a safe stop with lockout-tagout procedures.

External setup is work that can be performed while the machine is still producing. Fetching tools, preparing materials, reading instructions, and organizing the workspace.

In many factories, a large portion of the external work is done while the machine is stationary. Moving this work to before or after the actual stop can in itself shorten the changeover time by 30 to 50%, without requiring any individual activity to be done faster.

Step 2: Convert internal to external

The next step is to see which internal elements can be turned into external ones with small modifications. Pre-heated tools can be installed directly without waiting. Quick-connect couplings mean that a process that previously required dismantling can be connected in just a few seconds. Standardized fixtures eliminate adjustment steps.

This step often requires small investments in equipment or workspace design. These are almost always minor in relation to the value of the capacity that is freed up.

Step 3: Streamline both internal and external

The third step is about making every remaining element as fast and reliable as possible. Parallel work where multiple people can perform different tasks simultaneously. Standardize the working method so that two operators can perform the changeover in the same way. Visual aids and checklists help ensure that nothing is forgotten or done in the wrong order.

This is where the fine-tuning happens. The first 50% of the time gains often come from steps 1 and 2. The rest comes from persistent work in step 3, often over several months.

What is the most common mistake in changeover work?

The most common mistake is assuming you know how long changeovers take without actually measuring them. In most factories, the actual changeover time is 30 to 80% longer than what management believes. Gut feeling says one thing, measurement says another.

There are several reasons for this. Often, only the time when the machine is stationary is counted, not the time to ramp up to full speed with approved quality. Minor stops and adjustments during the first hours after the changeover are often missed. And changeover times often vary greatly depending on the product, day, shift, and operator, making the average figure misleading.

Before you can reduce changeover time, you must know what it actually is. This requires measurement that captures:

• From the last approved unit of the previous product

• To the first approved unit of the next product

• Including warm-up, fine-tuning, and quality verification

• Per product transition, per shift, per operator

With this data made visible, something unexpected is revealed. The difference between a fast and a slow changeover of the same product transition is often huge. That variation is gold. It shows that improvement potential already exists in the factory, among your own operators. The only question is how to get everyone working at their best.

What does operator involvement mean in changeovers?

Operator involvement means that operators are the driving force in the improvement work, not just recipients of instructions. The factories that succeed in long-term changeover improvements have something in common.

There are two reasons. First, operators see details that no one else sees. Which tools are missing on site? What adjustment steps are required on a certain line but not on another? Which steps hinder parallel work? This knowledge is not found in time studies from a consulting team. It is found on the shop floor.

Second, the change only lasts if the operators own it. A standardized way of working dictated from above will erode within a few months. A standardized way of working that the operators themselves have built and refined lives on.

At Bostik in Helsingborg, which manufactures adhesives and sealants with over 80 products on the same site, this was explicitly emphasized in the improvement work. Through systematic DMAIC work with the operators, changeover times on the filling machines were reduced by 70%. And OEE improved by 40%. One of the clearest insights during the work came from a seemingly simple observation: two operators working together on a changeover completed it faster than two working on separate machines. This is not an assumption. It is a measurement that the platform made visible, which then became a new standard way of working.

What should a system do to support changeovers?

A system should do four things: measure changeovers consistently, visualize the variation between changeovers, link the measurement to products and stop causes, and support the work in daily operations. This makes changeover work systematic instead of a one-off project that loses steam.

Measure changeovers automatically and consistently. From the last approved unit to the first approved unit, per product transition, per shift, per operator. Manual measurements wear out. Automatic ones last.

Visualize the variation. An average changeover time says little. The spread between fast and slow changeovers of the same product transition says a lot. It should be visible directly in the platform, not require a separate BI analysis.

Link to products and stop causes. Some product transitions are expensive. Others are cheap. Being able to prioritize the most expensive transition, or the one that occurs most frequently, is the difference between structured improvement work and random effort.

Support the work in daily operations. Changeover times must be shown on the dashboard in the morning meeting and in the weekly meeting for improvement work. Otherwise, it becomes a monthly report that no one acts upon.

This is close to the core of what an OEE system should do. Measurement is the means. Improvement is the goal. The platform becomes the engine for daily work, not a reporting system that lives on the side.

How do you get started with shortening changeover times?

Get started with six steps. Choose a critical product transition, measure for three weeks without changing anything, video record the changeover, classify each element as internal or external, introduce a standardized way of working and test run, and scale only when it works.

1. Choose a critical product transition. Not the easiest. Not the hardest. Choose one where changeovers occur frequently and where an improvement would free up visible capacity. That is where evidence can be built.

2. Measure for three weeks without changing anything. Get an honest baseline. Include the variation between operators and shifts.

3. Video record the changeover. It is impossible to overstate the value of this. What the operators believe happens, and what actually happens, often differ dramatically. The video becomes the basis for analysis.

4. Classify each element as internal or external. With a stopwatch and the video as a reference, gather the operators around a table. Discuss every element. Determine what can be moved, what requires equipment, and what just requires discipline.

5. Introduce a standardized way of working and test run. Write it down. Put up visual aids. Test run ten changeovers with the new method. Measure. Adjust.

6. Scale when it works. Not before. When the first product transition is faster and the results hold across shifts, spread it to the next product transition and the next.

It is quick to gain a lot. It takes perseverance not to slip back into old habits.

How does Good Solutions work with changeovers?

The platform from Good Solutions is built to drive improvement work in daily operations. This also applies to changeovers. Automatic measurement captures the time from the last approved unit to the first approved unit, per product transition and per shift. Variation is visualized in dashboards that operators, production leaders, and improvement teams use in their regular meetings. Stop causes and product data are linked so that the right efforts can be prioritized.

Operational implementation is just as important as the software. The platform is delivered with expert support from implementation consultants with production experience. The training program for operators and superusers ensures that working methods are implemented. A dedicated Customer Success Manager follows the customer over time.

Among the results is Bostik, which shortened changeover times on filling machines by 70% and improved OEE by 40%. System 3R, a Swedish company in tooling and automation solutions, has a declared goal of reducing changeover times to under ten minutes, in line with the original SMED ambition. Today, the platform supports 300+ factories, from individual lines to multi-factory groups.

Read more about how others have increased their factory productivity

FAQ

How much is it possible to shorten changeover times?
Experience from various industries shows that an improvement of 30 to 50% in the first year is realistic with a systematic SMED methodology. Factories that work persistently for 2 to 3 years often reach further, sometimes 70% or more. The largest part is won early, by separating internal and external setup. The rest comes from persistent work with each sub-element.

Do we have to invest in new equipment to shorten changeover times?
Not in the first instance. A large part of the improvement comes from methods and organization. Moving external work from downtime to runtime usually only requires new working methods. Later investments in quick couplings, pre-heated tools, or standardized fixtures can yield further results, but they should come after the basic work is completed.

Who should lead the changeover work?
Continuous improvement management, production management, and operators together. Improvement management is responsible for the methodology and follow-up. Production management ensures time and resources for the work. Operators drive the practical execution. Without operator involvement, the change will not last.

How do we measure a changeover correctly?
From the last approved unit of the previous product to the first approved unit of the next product, including warm-up, fine-tuning, and quality verification. Measurement should occur automatically, per product transition, per shift, and per operator, so that variation is visible. Manual measurements are a reasonable first step but do not hold up over time.

How do we know that the improvement lasts?
Through continuous measurement. Changeover times should be visible on the dashboard in daily operations, not reported monthly. When the variation between changeovers begins to increase again, it is an early sign that working methods are eroding. That is when the daily routines should be reinforced, rather than questioning the measurement.