Single Minute Exchange of Die

Single Minute Exchange of Die ( SMED; German: Tool change in the single-digit minute range ) means, in relation with Quick Change Over ( QCO to German fast setup ) a method to reduce the setup time of a production machine or a production line. The term " tool change " here is misleading, since the time of the last major chunk of the old production batch for the first major chunk of the new production batch is meant and is better described as " production changes ". The difference is that not a waste of time of changing a tool is essential, but also things like the provision of new material or the parameterization of the machine and the like; that is, the total time which can not be produced.

Goal of SMED is to reduce stocks by umrüstet the machine to a new manufacturing process, without disturbing the flow of production. The final aim can be considered to be reached when a machine or a production line within a production cycle can be converted, so that even with a wide variety of products implemented a one -piece flow, or even better yet a Mixed Model One Piece Flow can. In this case, the balances in the line are equal to zero.

Was developed by Shigeo Shingo, the process, who was involved as an external consultant instrumental in the development of the Toyota Production System (TPS). Implementation: In several iterative steps, the setup time is improved only by organizational and technical measures later. To minimize the cost, it is important that the steps in the order to be passed through. The experience is that each step in each case leads to a reduction in set-up time of 50 to 60 % ( with respect to the previous step). Larger investments are thus, if ever, made ​​only at a very late stage.

SMED runs in four (five) steps:

These steps are repeated through until the setup is in the single digits of minutes, each following step, in relation to the previous one, usually leads to disproportionate investment.

An essential element in the implementation is to divide setup procedures in internal and possible external steps and go through the external operations while the machine is still in production or produced again.

  • Internal steps can be performed ( eg tool change ) only when machine is stopped.
  • External steps may be performed when the machine is still produced (for example, providing the tools and precursors).

To optimize a variety of techniques, such as:

  • Preparation of the production change
  • Use of clamps instead of screws
  • Slide tables instead of cranes
  • Separate preheating
  • Between clamping means for adjusting outside the machine
  • Parallelization of set-ups - at the same time instead of one after the other - that is, instead of using more than one employee (often regarded as a fifth step)
  • Elimination of adjustments
  • Mechanization
  • Standardization of setup activities
  • Standardization of tool dimensions

Further developments of the SMED method are:

  • Zero -Change Over: retooling within three minutes
  • OTED ( = One Touch Exchange of Die ): conversion by arm movement

Disadvantages by SMED for the employee

The employees of a company provide suggestions that lead to faster set-ups, as part of a group working session during working hours, ie ideas and thoughts of each individual are recorded on a flip chart, evaluated and feasible proposals will then be possibly applied in practice. In addition, there are many large companies the company suggestion scheme ( BVW ), evaluated at the written proposals submitted, and feasible proposals will then be possibly implemented in practice. This may result for the employee a bonus for his proposal. Does the company have no control group for the evaluation of proposals from led working groups ( facilitated workshops ) and prohibits the payment of a control premium in this case, does not apply to the employees the direct financial reward for his suggestions. However, there is the employee responsible to bring his proposals in the workshop, or submitted only in the wake of a personal suggestion for improvement.

Whether employees threaten or secure their own work through their ideas for improvement, depends in part, in any economic situation, the establishment is located. In companies with under-utilization Rüstzeiteinsparungen may be associated with personal savings in the short and medium term. In busy companies, in line production especially at the bottleneck equipment, time savings can normally be implemented in more production and possibly lead to staff numbers. In both cases, however, the company can increase the long term through increased productivity and flexibility its competitiveness and secure jobs in their own companies.

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