Processing Time Relationships 

Use

A relationship with a minimum or maximum time interval can exist between two activities. (You define time relationships in the source of supply for in-house production.) At the start of the optimization run, the system evaluates the relationships between the activities and then determines the possible scheduling dates/times for the activities.

·        Relationship between two non-fixed activities

During optimization, the system must always adhere to the relationship between two non-fixed activities; they represent a hard constraint. The system is not allowed to drop below the minimum interval, and the maximum interval must not be exceeded.

·        Relationship between a fixed and a non-fixed activity

Using the relationship between a non-fixed activity and a fixed activity, the system determines the earliest or the latest start or finish dates/times for the non-fixed activity. These dates represent hard or soft constraints for the optimization as follows:

¡        Earliest start or finish dates/times are a hard constraint for the optimization.

¡        By default, latest start or finish dates/times are soft constraints that the system is allowed to violate. These delays can be minimized during optimization.

The following table provides a summary of the dates/times defined by a relationship to a fixed activity. The relationship goes from the first activity to the second.

 

First activity	Second activity	Type of interval	Date/times defined by relationship
Fixed	Non-fixed	Maximum interval	Latest start or finish date/time
Fixed	Non-fixed	Minimum interval	Earliest start or finish date/time
Non-fixed	Fixed	Maximum interval	Earliest start or finish date/time
Non-fixed	Fixed	Minimum interval	Latest start or finish date/time