Introduction¶

About this guide¶

This guide details all constraints that can be applied when scheduling and how they affect the plan generated by the Dynamic Scheduling Engine. Constraining an activity determines when it can be scheduled and who can complete it.

Introduction¶

There are many constraints which affect how the Dynamic Scheduling Engine may allocate activities to resources. Some of these are hard constraints which must be obeyed in order for an activity to be allocated, and others are soft constraints which give a preference for allocating an activity to a particular resource, or at a particular time.

When getting started with scheduling, it is best to start with no constraints and gradually add them in one at a time, reviewing the schedules as you go. There is always a danger of over-complicating the constraints, which will result in fewer activities than expected being allocated, or slow performance.

In real-life situations, customers are often replacing a system of human scheduling with IFS Scheduling. Humans will be working to hard constraints, but if an activity cannot be allocated to anybody they will often have a way of overriding the constraint, in order to get the job done. With the Dynamic Scheduling Engine, hard constraints will never be broken, so the DSE would just leave such activities unallocated. During implementation, it is important to decide whether these hard constraints should actually be soft constraints (preferences), or whether they should remain as hard constraints, and if activities are unallocated because of them then the customer will manually intervene to allocate the activities.

A user has the option to manually schedule an activity, either by committing it to a resource, or by fixing it to a resource and a time. If an activity is committed to a resource, it will obey any time constraints if parameter CommittedActivitiesConstraintsOption is set to do so, but otherwise time constraints will be ignored, and resource constraints are, in any case, overridden. If an activity is fixed to a resource and a time, then all constraints are overridden.