1. The confusion might stem from the fact that the names Products and Processes are both used in two different ways: as OPTMODEL sets and as SAS DATA sets. In this example, except for the first word after READ DATA, they always refer to OPTMODEL sets. To help see what is going on, I recommend using the PRINT statement after the second READ DATA statement populates the RequiredTime parameter:
print RequiredTime;
2. To see what the CON statement is doing, I recommend using the EXPAND statement:
expand Availability;
You will see four constraints (one per member of the Processes set), as in the previous PROC OPTMODEL session in this example.
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