What is SMED?

It is a Lean Manufacturing tool used to reduce reference changes within a productive environment. SMED (Single Minute Exchange of Die, or tool change in a single digit of a minute)

Before starting we must be clear about the following concepts:

Internal change process: These are operations that can only be done with the machine stopped.

External change process: are the operations that can be carried out with the machine running.

· Change time: It is the time between when the last part of the previous reference is produced until the first OK part as the new reference. Therefore, it is the sum of internal and external change processes.

To carry out this function, it is essential to create a multidisciplinary team with people with experience in the change process:

- People who make the changes.

- Technical and / or maintenance staff

- Continuous improvement or organizational staff.

- Others necessary (security, quality, logistics, etc.)

For this, a filming of the change must be made, trying to capture each of the operations that are carried out. The characteristics of the change must be taken into account, such as the number of workers, the duration and the trips, if any.

Recording begins just when the last part is produced and ends when the quality of the next reference is validated.

In a meeting room with the SMED team we will begin to analyze the change of format by following the following steps:

- First stage: Separate internal processes from external ones.

Team members will differentiate one by one and discard external processes as they will be standardized outside of change. Check-lists are frequently used to organize the preparations for change.

- Second stage: Convert internal to external.

For each of the activities that have been defined as internal, actions must be taken to extract them from the time of change. For which actions oriented to the transport of parts and storage are usually undertaken.

- Third stage: reduce the time of internal activities

Along with the previous one, the ingenuity and experience of the members come into play. It is about carrying out multiple actions that reduce the time of the internal activities that remained.

- Standardization: Once the actions are carried out, the changes will be made in a standard way that has been defined in the workshop.

- Tracing: the team should keep track of the improvements made.

Customers increasingly demand differentiated products and smaller batches, so the option of manufacturing large series is not viable. A solution is in reducing format changes that allows increasing references, reducing inventory and customer waiting time.

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