Friday, September 12, 2008

Steps to shorter setups

We have seen that separating the internal and external elements of a setup, and carrying out the external elements while the value is still being created, is the first and usually largest part of reducing setup time.

The complete list of steps to minimizing setup time is:

  1. Separate internal from external, and carry out external operations while value is still being created.
  2. Carry out the internal operations as several simultaneous operations.
  3. Convert internal operations to external operations.
  4. Simplify and automate all remaining internal operations to speed them up.

Briefly, these steps are understood as follows.

Carry out internal operations as several simultaneous operations: This is often referred to as “parallel work”. The typical image is of the race car pit stop, where four tires are changed, fuel is topped up, the wing is adjusted, and so on, in just a few seconds. Anyone who has watched a car race will have seen how this is done – utilizing five, six, or more pit crew. By analyzing the tasks of the pit stop, and dividing the work into tasks that can be done simultaneously, the internal work is done in a fraction of the time it would take if only one task was done at a time.

Convert internal operations to external operations: Many internal tasks consist of replacing and assembling several parts of a machine, a file of information, a kit of some kind, and any other setup that has several components. Take the above example of the pit stop – a tire change consists of replacing a tire mounted on a rim. By mounting the tire on a rim prior to the pit stop, what would otherwise be an internal activity (putting the tire on the existing rim) has been converted to an external activity, at the expense of having an extra rim. Another example is the use of a kit of materials, tools, parts, etc., that eliminate searching and selecting. A large part of internal operations that is usually considered separately is measuring and adjustments, to assure that the value creating operation produces an output that meets specification. By standardization, these operations can be eliminated.

Simplify and automate all remaining internal operations to speed them up: Further setup reduction allows value creation to more closely match demand economically, but safety, repeatability, and ergonomics must not be sacrificed. This calls for simplification and automation of tasks such as fastening, moving, data entry, and communication. Special tools and programs, codes and signs, design for changeover, and other similar approaches are utilized to gain speed.

It is, of course, also necessary to apply some of these techniques and technologies to the external setup. With shorter setups, and shorter periods of value creation between setups, external operations must be carried out in less time. This means better organization, simplification, mistake proofing, and automation.

1 comment:

Mikel Lorente said...

SMED technics are good for one part of the formula. The target of the company is minimizing total time spent in changeover. That is time spent in a single change (SMED) multiplied by the number of changes. The second part is related with production planning. There are software solutions that use mathematical algorithms that try to minimize changeover time (and other things such as average delays). Take a look to Grupo i68´s izaroaps Advance Planning & Scheduling Solution to know more about APS and their relation with Lean manufacturing.
Izaro APS
Grupo i68