Page 192 - ExtendSim User Guide
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166 Routing
Items going to several paths
Scrap generation
An important aspect of some systems is modeling the generation of scrap or simulating a yield rate. For instance, many manufacturing processes create an expected but irregular quantity of waste or bad items. This can be accomplished in ExtendSim by randomly routing some items out of the normal processing stream.
Scrap Generation model
This example is similar to the model that is described in “Simple unbatching” on page 217, except it has a Select Item Out block that determines whether items coming from the Unbatch block should continue for processing or be discarded, and the Activity block processes two items at a time. The Select Item Out block is set to Select output based on: random. By set- ting a probability that 0.90 of the items will exit through the top connector and 0.10 through the bottom (scrap) connector, the Select Item Out block causes one out of every ten items to become scrap.
Scrap Generation model
As an alternative, you can also set and check attributes to represent items that need to be scrapped. This will be shown later in this chapter.
Sequential ordering
To hand items to operations in successive order regardless of whether another operation is free, use the Select Item Out block set to Select output based on: sequential.
Discrete Event

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