If you fix an operation, the operation will not be moved from the resource and time to which the operation is fixed as much as possible when rescheduling.
The following types of fixing are available.
Fixes the resource to which the operation is assigned. Since the assigned time is not fixed, the operation can be moved timewise when rescheduling.
If the assigned resource of an operation is fixed, short blue horizontal lines will be displayed under the bar.
Fixes the time to which the operation is assigned. Since the assigned resource is not fixed, the operation can be moved to other candidate resource when rescheduling.
If the assigned time of an operation is fixed, short blue vertical lines will be displayed under the bar.
Fixes the resource and time to which the operation is assigned. The same status as when both resource fix and time fix are set for the operation.
If an operation is full fixed, short blue vertical and horizontal lines (looking like L-shaped marks) will be displayed under the bar.
The status in which an operation is not fixed.
Use Instruction Fix
Fixes the resource of a use instruction. "Resource fix" of an operation will fix all resources assigned to the operation, however, "Use instruction fix" will fix each use instruction of an operation. For example, you can use "Use instruction fix" when you want to fix a sub resource only.
If the resource of a use instruction is fixed, short red horizontal lines will be displayed under the bar.
When a fixed operation cannot be assigned to the fixed time due to reasons such as no working time, insufficient resource quantity, and setting of suspend time MAX straddling working time, the operation will be moved and assigned to an assignable time period when rescheduling.
When a fixed operation cannot be assigned to the fixed resource due to reasons such as deletion of the assigned resource from master data, disabling of the assigned resource, and a "FALSE" result from the valid condition of the use instruction, the operation will be assigned to a dummy resource when rescheduling.
Note, however, that in the case of the following resource constraints, the operation will not be assigned to a dummy resource but to the fixed resource ignoring the constraints.
- Resource:Spec #
- Resource:Num spec # MIN, Num spec # MAX
- Resource:Next resource constraints
- Resource:Valid condition
- Use instruction:Next resource constraints
The above behavior of ignoring the constraints is the same for any cases of fixing, i.e. "Full fix", "Resource fix", and "Use instruction fix".
If you set the property "Assignment message level " of the project settings to "Detailed", a message describing ignored resource constraints will be output.
For next resource constraints, the constraints will be ignored only for fixed operations. Therefore, in cases where one of resources before or after a next resource constraint is fixed, scheduling results may differ in backward scheduling and forward scheduling. In that case, we recommend fixing both of them.