Types of Scheduling Problems

A sequence for each product in which operations are to be performed 

A set of processing times for each product on processing units. The batch 

A matrix of transfer times for each product from each equipment item A matrix of setup times or costs between every pair of products in each equipment item. These setup times can be unit and product dependent and may be different for each sequence. 

Constraints on the production order for some products. There may be constraints due to demand patterns, where production targets have to be met, or resource constraints such as labor or utihties. 

The nature of intermediate storage between processing stages. Four different storage options are defined  

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Another complication in this type of scheduling problem is that the production steps are sequential R S R This means that when a reactor has finished producing a product, the separator should be available to carry out the next step in the process, and, similarly, the precipitator should be available when the separation has finished. This problem was chosen with the assunption that the separator and precipitator are always available to handle the products from the reactor, because the longest processing time for a given piece of equipment is always shorter than the shortest time for the preceding operation (4 < 7, 3 < 4). For this case, the solution to the problem is sinple because the only piece of equipment that must be considered is the reactor the reaction step is the limiting step in each process. 

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