Note:
The MilestoneToMilestone relationship must be modeled between all possible combinations of milestone pairs that may appear in the plan item in the execution plan generated by AOPD. Although the product model can have any number of milestones defined, the actual plan item may contain only the subset of these milestones due to the dependency modeling and the products being ordered.
Assume that PF_PROVIDE is a plan fragment associated to a product P1 for PROVIDE action in the product model. Also, it contains four milestones namely START, M1, M2, and END. Now, based on the dependencies modeled and the products ordered, one of the three milestone combinations given below can come into the plan item generated for fulfillment of P1.
- START, M1, END
- START, M2, END
- START, M1, M2, END
In order to support any of the three milestone combinations mentioned above, the MilestoneToMilestone relationships must be modeled for the following milestone pairs so as to have the corresponding sections in the plan fragment model.
- START->M1
- START-M2
- M1->M2
- M1->END
- M2->END
While processing this plan item in the execution plan reply, Orchestrator finds the required plan fragment sections in order to sort the milestones in a proper sequence based on the typical duration value. This ensures correct representation of the plan item on OMS UI Gantt chart. If any of the required section is missing in the plan fragment, Orchestrator fails with an exception to process the execution plan.
For example, in the case of the START-M1-M2-END combination, the sequence of M1 and M2 after START is decided on the basis of the typical durations for START->M1 and START->M2. If START->M1 is 2000 ms and START->M2 is 1000 ms, milestone M1 is sequenced after M2. So the sequence is START->M2->M1->END.