We know how to define the tasks and the durations efficiently simply by crossing the elementary tree structures Products (PBS), Activities (ABS) and Zones (ZBS) in interfaces matrix. We can use the WBS matrix for that, or Cubix360for those who don’t know how to do it in VBA EXCEL.
The tasks (WBS coming up to the tasks) are the crossing between ZBS, PBS and ABS. Activities are deployed on Products which are sometimes instantiated and then assigned into a Zone.
For the duration, we use, in the WBS matrix/Cubix360, the formula: Duration = Quantity x Unit Rate, with:
- Unit rate = standard duration between Products and Activities, in working days;
- Quantity = Coefficient function of the volume of works/complexity of the Zones.
For the relationships, I think the best way to define it is to use interface matrix, as shown below:
For instance, for Activities, we must do first A2, then A4, A5 and A7. We can put Finish to start logical links. But if into a Product’s process there is no the Activity A5 (in the structuration part), then we have the sequence A2, A4, A7.
We have to understand that Activities are deployed on Products, and then when 2 Products are linked, it is in fact the 2 activities of the 2 Products that are links, for instance we have P1(A5) linked to P4(A6).
Same thing for the Zones, when 2 Zones are linked, it is in fact 2 Products that are linked including 2 activities, for instance the relationship Z2(P3, A3) to Z5 (P5, A7).
Activities relationships have 1 dimension, Products relationships have 2 dimensions, and Zones relationships have 3 dimensions.