The CLP Procedure

Modes of Operation

The CLP procedure can be invoked in either of the following modes:

  • The standard mode gives you access to all-different constraints, element constraints, GCC constraints, linear constraints, reify constraints, ARRAY statements, and FOREACH statements. In standard mode, the decision variables are one-dimensional; a variable is assigned an integer in a solution.

  • The scheduling mode gives you access to more scheduling-specific constraints, such as temporal constraints (precedence and time) and resource constraints. In scheduling mode, the variables are typically multidimensional; a variable is assigned a start time and possibly a set of resources in a solution. In scheduling mode, the variables are referred to as activities, and the solution is referred to as a schedule.

Selecting the Mode of Operation

The CLP procedure requires the specification of an output data set to store one or more solutions to the CSP. There are four possible output data sets: the Solution data set (specified using the OUT= option in the PROC CLP statement), which corresponds to the standard mode of operation, and one or more Schedule data sets (specified using the SCHEDULE= , SCHEDRES= , or SCHEDTIME= options in the PROC CLP statement), which correspond to the scheduling mode of operation. The mode is determined by which output data set has been specified. If an output data set is not specified, the procedure terminates with an error message. If both types of output data sets have been specified, the schedule-related data sets are ignored.