CIP rules

A CIP step is associated with a rule. This step is used to create a CIP batch with the default step quantity.

This table shows the various types of CIP rule:

Rule	Description
Absolute time	A CIP batch can be scheduled after the time T when this condition is verified: The duration T minus the start of a batch that follows the last CIP batch exceeds a specified duration.
Number of batches	A CIP batch can be scheduled after a specified number of batches since the last CIP batch.
Processing time	A CIP batch can be scheduled when the sum of the process segment durations since the last CIP exceeds a specified duration. Processing time is used to schedule a CIP batch after the resource has been used for a specified period of time. Unlike absolute time, processing time does not count the resource's idle time, for example, the time between process batches.
Quantity	A CIP batch can be scheduled when the sum of the batch quantities since the last CIP exceeds the specified quantity.
Transition cost	A CIP batch can be scheduled when the sum of the transition costs since the last CIP exceeds the specified quantity. If the duration or quantity of a batch is not considered; however, specific events require a CIP batch, you can use a cost matrix for modeling. Each batch contributes to the sum of the transition costs since the last CIP. The contribution of a batch is determined by the changeover cost to the corresponding batch. The cost of the first batch on a resource is determined by the gauge cost, or zero if no gauge cost is specified. The cost of the last batch on a resource is the transition of the batch criterion to NONE.

These are the limits or constraints for CIP modeling:

• Minimum

  The minimum duration, number, or quantity determines the minimum number of process batches that must be scheduled after a CIP batch. This constraint can only be used for these rule types:

  • Quantity
  • Processing time
  • Number of batches
  Note: This constraint is not used when the value is set to zero.
• Maximum

  The maximum duration, number, or quantity determines the maximum number of process batches that can be scheduled after a CIP batch.

• Resetting the CIP count for large changeovers

  If large changeovers occur, you can run a CIP operation during these large changeovers. During a large changeover, although the actual CIP batch is not scheduled, the CIP operation is performed in the factory.

  If this option is enabled and a minimum changeover duration is defined, the CIP counter is reset by the solver each time a large changeover occurs. However, CIP batch is not scheduled. This option is not applicable for absolute-time CIP rules.

The gauge time and value can be used to specify a start value at a certain point in time for the CIP calculation.

These conditions are applicable for Solver calculations:

• If a CIP rule's gauge date is defined, the solver calculations start from the specified point in time, using the specified gauge value.
• If no gauge date is defined, the solver calculations start from the end of the last CIP batch on that resource, considering the starting value as 0.
• If CIP batch is not assigned to the resource, the solver calculations start from the beginning of the work area.
• If the CIP rule type is set to Absolute time and gauge date is not defined, the solver calculations start from the beginning of the first batch after the work area.