Updated on: 17.05.2022

SMED - Set-up time optimisation in maintenance and production

Subject area

Service Engineering | Systems Engineering

SMED - Optimisation in maintenance

SMED stands for Single Minute Exchange of Die. The method aims to optimise set-up times with regard to higher availability.

SMED - What is it about?

Many maintenance management methods aim to increase the availability of the production goods used. Especially the set-up times associated with a tool change can have a great influence on the productive time of the machine or system for small production batches. According to the motto "time is money", the implementation of continuous improvement processes attempts to optimise set-up times on an ongoing basis.

  • SMED stands for "Single Minute Exchange of Die".
  • Methods and activities for the systematic reduction of set-up times
  • Set-up times in the single-digit minute range are to be achieved
  • SMED, like many other lean methods, aims to minimise waste in production processes

SMED - Basics

The SMED concept also has its origins in the Toyota production system. Following the ideal of one-piece flow, set-up processes should run synchronously with the higher-level flow cycle of the production system. In addition to the levelling of the cycle, SMED represents one of the essential LEAN methods. The following principles, among others, are applied:

  • Separation of the setup process into internal and external setup
  • Standardisation of the retrofitting and conversion processes
  • Technical adjustments to machines and tools
  • Introduction of innovative set-up aids
  • Optimisation of logistics processes

Total set-up time in view

With the SMED method, however, the focus is not only on the time for the actual tool change or changeover process. It is important to take an overall view, including the times for shutting down and starting up production.

A look at the diagram opposite makes it clear why. A pure focus on the actual downtime ignores the fact that significant production losses already occur when the plant is shut down and even more so when it is restarted.

Within the framework of the SMED analysis, it therefore makes sense to distinguish between the following time periods.

(1) Run-down: Power reduction until standstill

(2) Set-up: Actual set-up process

(3) Run-up: performance increase to the target level

Set-up times from the perspective of the SMED method
Division of set-up time at SMED into different time zones

Assembly-friendly design as a driver of SMED optimisation

Technological adaptations of assembly and joining processes in particular hold great potential for optimisation, and small design changes can lead to a significant reduction in set-up time.

  • Plugging instead of screwing
  • No need for adjustment with quick-release fasteners
  • Devices and joining aids for better positioning and clamping
  • Modular design, simplifying external set-up and parallelisation of operations

SMED optimisation procedure

The process of SMED optimisation is comparable to other quality management optimisation methods and also follows the PDCA cycle to a certain extent, although SMED is to be understood less as a project and more as a continuous task. In general, the aim is to break down the entire process into individual sequences and to consider at each point how the time required can be reduced or the complexity of the task implementation can be lowered.

SMED Optimisation - Procedure

Implementation of a SMED optimisation project

  1. Analysis of the actual situation

    The starting point is a detailed observation and documentation of the current set-up process. It is a good idea to divide the entire set-up process into individual sequences and to record the manual activities and the tools and aids used for each step. This simplifies the SMED analysis afterwards.

  2. What steps and activities could take place beforehand or afterwards?

    As already mentioned, one of the main concerns of the SMED method is the separation of internal and external makeready operations. Which steps can only take place at standstill (internal) and are an integral part of the makeready operation? Which steps can take place upstream or downstream in time (external)?

  3. Standardisation and structural optimisation

    It is not only by outsourcing individual activities that a reduction in set-up time can be achieved. Another central element of SMED is the harmonisation of workflows. With industrial engineering methods, additional valuable seconds can be saved.

  4. Testing of technological innovations

    Are new methods, measuring principles or tools available? Especially with tried and tested processes, it is worth checking now and then whether new technologies can be used.

Observe and measure

In a first step, the process flow must be precisely recorded and quantitatively described. In this phase, it is useful to work with video recordings of the current procedure. Afterwards, the entire process can be divided into individual steps and timed. Ideally, the team works as usual and is accompanied by two to three people, one of whom makes the video recordings and the others observe the process.

In the follow-up of the observation phase, the following questions should be able to be answered:

  • What activities and activities are carried out?
  • What is the average execution time for each activity?


After observation and recording, each sequence of work is to be analysed separately and assigned to a category.

  • Internal activities: Can only be carried out when the machine or plant is at a standstill.
  • External activities: Can be carried out when the machine is in operation, shutting down or starting up again.
  • Non-essential activities: Activities that do not really add value and can be dropped.


Creativity is now required in this phase. Can selected activities be redesigned so that they can also be carried out upstream or downstream? For example, instead of carrying out cleaning and adjustment work on individual components immediately, it can make sense to have a replacement pool available in many cases.

Standardise and optimise

If individual activities have a high spread in terms of time, the optimal procedure should be defined in the team and recorded as an SOP.

Simple measures, quick successes

Particularly in the first rounds of optimisation, comparably simple measures can quickly achieve success. Due to a lack of structuring in the past, time-consuming workarounds have developed in many cases that can be quickly identified and eliminated.

Waiting and searching

The lower the level of practice, the higher unnecessary dwell times tend to fall. Enormous potential can be unlocked through good documentation, pre-planning and best practice training.

Missing or suboptimal tools and materials

If the right tool is not at hand or if you don't even know that there is a suitable tool, then you will have to fiddle and fiddle. In the worst case, this can even lead to damage.

Missing checklists

It is not for nothing that checklists are a great optimisation tool. They are the first step towards standardising processes and increasing reproducibility. As long as one does not overdo it, i.e. the balance between execution time and documentation effort is maintained, pragmatic checklists can also lead to time savings.

SMED in maintenance

The approach to set-up times can of course be transferred to other maintenance operations. The SMED method can be transferred to all repair and maintenance activities. Especially for recurring operations, the potential is high due to the multiplication effect. Inspection checklists and work instructions in the CMMS should therefore be standardised across the board and regularly checked for optimisation potential.

Because the advantages have an impact on the entire production system:

  • Greater flexibility and agility
  • Manufacturing processes remain profitable even with smaller batch sizes
  • Reduction of fixed costs and inventories

Frequently asked questions - SMED

What are the key success factors of SMED?

Above all, it is important not to see the SMED method as a one-off project, but to firmly anchor the practical application in everyday work. Even more important, however, is the team concept: the application of the SMED principles must bring benefits for the entire team and must not lead to employees feeling additionally stressed by the continuous reduction of target times.

What is a SMED workshop?

A SMED workshop is an interactive team session with the aim of reducing the set-up time of a manufacturing process.

What does SMED mean?

SMED stands for Single Minute Exchange of Die and is a method of set-up time optimisation.