How can changeover time be reduced in manufacturing?

Changeovers are among the most underestimated sources of loss in the manufacturing industry. They are planned and visible in the schedule. They are often not counted as a "stop". But a changeover during which the machine stands 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 for increasing capacity, meeting varying demand, and improving OEE. And it is an area where improvements can often be made without major investments. It is a matter of methodology, measurement, and sustained effort.

This guide walks you through how to reduce changeover times using 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 process of continuous improvement. A platform that makes losses visible enables 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 on changeovers 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 performance. Shorter changeovers have the opposite effect: 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 change over quickly wins. While competitors with longer changeover times hesitate, you have already started producing the new item.

This strategic view means that changeover work should not be treated as an operational improvement 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 methodology for shortening changeover times in three steps: separate internal and external setup, convert internal elements to external, and streamline what remains. The term was coined by Shigeo Shingo in Japan during the 1950s and 1960s, and the original goal was to change tools in under ten minutes. The methodology has since become a cornerstone of lean and has been used successfully across all types of manufacturing, from automotive to food processing.

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 of the changeover.

Internal setup comprises work that can only be performed when the machine is completely at a standstill. This includes, for example, tool replacement, adjustments inside the machine, or other tasks that require a safe stop with lockout/tagout procedures.

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

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

Step 2: Convert internal to external

The next step is to see which internal elements can be converted to external with minor changes. Preheated tools can be installed immediately without waiting. Quick-connect couplings mean that a process that previously required dismantling can be connected in just a few seconds. Standardised fixtures eliminate adjustment steps.

This step often requires small investments in equipment or workspace design. These are almost always small relative to the value of the released capacity.

Step 3: Streamline both internal and external

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

This is where the fine-tuning happens. The first 50% of the time savings 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 believing you know how long changeovers take without measuring it. In most factories, the actual changeover time is 30 to 80% longer than management believes. Gut feeling says one thing, measurement says another.

There are several reasons. Often, only the time when the machine is stopped is counted, not the time to ramp up to full speed with approved quality. Minor stops and adjustments in the first hours after the changeover are frequently missed. And often, changeover times 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 a 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 changeover, per shift, per operator

With this data 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 during changeovers?

Operator involvement means that operators drive the improvement work, rather than being passive recipients of instructions. 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? Which adjustment steps are required on one line but not another? Which tasks prevent 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 standardised way of working dictated from above will erode within a few months. A standardised 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 line, this was a distinct focus in their 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 did it faster than two working on separate machines. This is not an assumption. It is a measurement made visible by the platform, 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, visualise the variation between changeovers, link measurement to products and stop causes, and support the work in daily operations. This turns changeover work into a systematic process rather than a one-off project that loses momentum.

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

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

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

Support daily operations. Changeover times should be displayed on dashboards in the morning meeting and the weekly improvement meeting. 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 on 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 task as internal or external, implement a standardised work method and a test run, and scale up only when it works.

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

2. Measure for three weeks without changing anything. Establish 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 operators believe happens, and what actually happens, often differ dramatically. The video becomes the basis for the analysis.

4. Classify each task as internal or external. Using stopwatches and the video recording as a guide, gather the operators around a table. Discuss each task. Decide what can be moved, what requires equipment, and what just requires discipline.

5. Implement a standardised way of working and test run. Write it down. Put up visual aids. Run ten changeovers using the new method. Measure. Adjust.

6. Scale when it works. Not before. When the first product transition goes 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 requires perseverance to avoid falling 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 for each product transition and shift. Variation is visualised in dashboards used by operators, production leaders, and improvement teams in their ongoing meetings. Stop causes and product data are linked together so that the right actions are prioritised.

Operational implementation is just as important as the software. The platform is delivered with expert support from delivery consultants with production experience. The training program for operators and superusers ensures that work 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 an explicit goal of reducing changeover times to under ten minutes, in line with the original SMED ambition. The platform today supports around 300 factories, from individual lines to groups with multiple factories.

Read more about how others have increased their factory productivity

FAQ

How much can changeover times be shortened?
Experience across various industries shows that a 30-50% improvement within the first year is realistic with a systematic SMED methodology. Factories that work persistently for 2 to 3 years often achieve more, sometimes 70% or more. The largest part is won early, by separating internal and external setup. The rest comes from persistent work on each sub-step.

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 organisation. Moving external work from standstill time to running time usually only requires new ways of working. Later investments in quick-connect couplings, preheated tools, or standardised fixtures can yield further effects, but they should come after the basic work is complete.

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

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, adjustment, and quality verification. Measurement should be automatic, 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 the improvement will last?
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 the work practices are eroding. That is when the work around them should be reinforced, rather than questioning the measurement.