SMED (Single minute exchange of die), is a Lean Manufacturing technique that allows significant reduction of product changeover times of machines in production environments. SMED method means to convert as many changeover steps as possible to “external” (performed while the machine is running), and to simplify and speed up the “internal” steps (could be performed only when machine is stopped).
SMED was developed by Shigeo Shingo during the period of 1950-1969, when Toyota presented great losses in its lines of stamping due to the high changeover times of die between different references. This motivated Shigeo Shingo to introduce the idea that any change of product should last less than 10 minutes, with the phrase “Single minute exchange of die” emerging from there.
To understand how SMED works, it is necessary to review a series of basic concepts:
Changeover time: the time that elapses since the last piece of product A (outgoing product) comes out until the first piece “ok” of product B (incoming product) comes out.
Changeover operations: all activities necessary to carry out the format change.
Internal operations: all activities of change that can only be done with the machine stopped.
External operations: all activities that can be carried out while the machine is running.
It is essential for the implementation of SMED to have reliable and immediate data on the interruption times of the machine due to product changeovers, as well as product quality controls. These data allow us to establish the exact current changeover times, establish objectives, make well-supported decisions about them and achieve their continuous improvement.
The M-Box production monitoring system collects the relevant and unbiased data in real time for analysis to ensure the optimal implementation of SMED, and thus advance the path of improving productivity and flexibility of Lean Manufacturing.