Single Minute Exchange of Die (SMED) | A technique called SMED was developed to reduce the readjustment time of equipment.
For a long time, it was believed that the effective operation of the enterprise implies the maximum possible load of equipment, i.e., a long operating time of the equipment after each readjustment.
To do this, the production was built in such a way that the number of readjustments was minimal, and the launch batches, respectively, large. This caused the accumulation of a huge amount of inventory at all stages of technological processes, which is typical for mass production.
The situation changed when TOYOTA developed a different concept of production organization (lean production). The result of the fight against production costs, in the company TOYOTA, was the work in small batches, passing through all stages of technological processes with the use of a “pulling” supply system (kanban system). This made it possible to reduce the area for storage within the enterprise, significantly increase working capital by reducing the stocks of unfinished production and gain many other competitive advantages.
To organize production in small batches, it is necessary to make frequent adjustments of equipment, so for any enterprise seeking to increase its profitability, reduce the cost of production and withdraw maximum cash to working capital, it becomes vital to reduce the time of reconfiguration of equipment. For this purpose, a technique called SMED was developed to reduce the readjustment time of equipment.
Benefits SMED
Benefits that can be derived by reducing the readjustment time of equipment:
- Reduced inventory. When working in large batches, parts that lie motionless and are waiting for their turn for further processing or assembly represent “dead” money for the enterprise, which can be withdrawn into working capital (revive).
- As a consequence of a decrease in inventories, the release of space. The vacated space can be used: for reinstalling equipment when building production flows in order to reduce the movement of parts and eliminate inter-operational stocks, to expand production or for leasing.
- Improvement of quality indicators. When working in small batches and frequent readjustments, the percentage of defects decreases, since more frequent readjustments are more frequent settings for the specified parameters.
The essence of the changeover process.
The readjustment process is a sequence of actions consisting of elements and transitions performed to configure the equipment after the release of one type of product for the release of another.
A distinction is made between internal and external readjustment.
Internal readjustment consists of work that cannot be performed without stopping the reconfigurable equipment.
External readjustment is the work that must be done to carry out the readjustment, but which can be performed without stopping the reconfigurable equipment (i.e., performed in parallel, during the production of products).
5 Steps SMED
Create a team.
The most effective task of reducing the time of adjustment of equipment is solved by working groups consisting of:
– Production specialist – group leader;
– Specialist in the development of the production system – methodical head of the group;
– Specialist from the Chief Technologist;
– specialist from the service department;
– etc.
The leader of the group sets specific, measurable goals for the rest of the project participants.Description of the readjustment process.
The group goes to the production site (Gemba) and initially describes the current state, breaking down the process into its constituent elements and transitions. Next, timing is carried out and in parallel – the identification of problems affecting the safety and execution time of the elements.
Separation of internal and external readjustment, transformation of internal to external.
The team determines which elements are internally readjusted and which are performed without stopping the equipment. A list of technological equipment necessary for the reconfiguration is drawn up. The analysis of the collected data is carried out. (On adjustments for different types of products). The possibility of performing elements of internal readjustment without stopping the equipment (conversion of internal changeover to external) is determined.
Reduction of internal readjustment.
The possibility of combining and reducing individual elements of internal adjustment is being considered.
Reduction of external readjustment.
The possibility of combining and reducing the elements of external adjustment is considered.
To achieve the best result at all stages of the implementation of the SMED system. It is recommended to brainstorm the problems. The group in its entirety meets after each readjustment. The problems detected by each member of the group are read out in turn. Developed solutions to each problem are recorded, from them the most effective and low-cost ones are selected. Next, the group leader determines which of the group members. And which proposals will be supervised and implemented.