Resource Scheduling Rules
Open Plan follows a number of general rules when performing resource scheduling.
These rules are as follows:
- Open Plan uses a serial method of resource scheduling. This means that activities are scheduled one at a time. Once an activity is scheduled, it is not reconsidered based on the needs of subsequent activities. The order in which activities are scheduled is determined by the project logic and can be modified only in a limited way by defining the priority fields used by the calculation.
Attention: For more information about defining priority fields, see Resource Scheduling Processing Options.
- Open Plan uses the late dates to determine when an activity is being delayed enough to delay the project completion. Therefore, if you change Time Now, you should rerun time analysis before performing resource scheduling.
- Resource scheduling does not violate project logic. Therefore, activities are available to be scheduled only after all their logical predecessors have been scheduled. While the order in which activities are scheduled is determined by the project logic, you can control the order to some extent by setting the activity priorities at run time.
- Resource scheduling does not violate project logic. This means that activities are available to be scheduled only after all of their logical predecessors have been scheduled. This means that no activity will be scheduled before its early dates.
- Open Plan does not schedule an activity before Time Now.
- Open Plan does not schedule an activity before its early start date.
- Activity durations are never shortened but may be lengthened due to stretching, splitting, or reprofiling. If lengthened in any of these ways, the new duration becomes the scheduled duration.
- You can tell if an activity is split, stretched, or reprofiled by viewing the Scheduled Actions field in the activity table.
- After resource-limited resource scheduling, an activity's resource requirements (on the scheduled dates) will not exceed availability except when using immediate activities, thresholds, or when scheduling is suppressed.
By assigning the Immediate attribute to an activity, you instruct Open Plan to start the activity on its earliest feasible date, even if that means overloading a resource. The earliest feasible date for an activity is a date calculated by resource scheduling and represents the earliest possible date an activity can start in the absence of any resource constraints on its schedule.
By assigning the Immediate attribute to an activity, you instruct Open Plan to start the activity on its earliest feasible date, even if that means overloading a resource. The earliest feasible date for an activity is a date calculated by resource scheduling and represents the earliest possible date an activity can start in the absence of any resource constraints on its schedule.
Attention: For information about immediate activities, see Resource Scheduling Attributes for Activities. - Time-limited resource scheduling schedules within the late finish date of the project if there is no negative float. If negative float is present, Open Plan schedules on the early finish date of activities with negative float.
If an activity is delayed, you can identify the first resource to delay this activity by viewing the Delaying Resource field in the activity table.
- Time-limited resource scheduling schedules critical activities first, as they cannot be delayed.