Recently, I planned a project of a factory whose main problems was piping; we had to provide an estimate of the durations of the schedule’s tasks and to have a vision of the remaining workload over the three months to come.
What is characteristic in the 3D model, it is that even the figures have three dimensions!
Thus, we calculated the durations of the schedule’s tasks according to a metric on the 3 axes of the cubic project:
- For the Zones, one used the number of isometric per room;
- For the Products, one used the number of hours to carry out the two main Products of the project for each building, I mean the supports and the pipes;
- For the Activities, one used volumes of work in % calculated by the number of hours necessary to carry out the installation of a support or a pipe.
By multiplying these three quantities, we obtained the relative durations of each of 2,500 tasks of the schedule. It remained us just to multiply them by a coefficient calculated with the duration of the critical path of the project, and also with pipes installation’s rate, to obtain a correct estimation of the durations of the whole of the tasks of this project which had already lived. This weighting was used to adapt the initial budgetary estimate to reality.
To measure the physical progress of a group of tasks on the 3 axes (Zones, Products and Activities) or of the project, one has to weight the tasks of the schedule, by using the well-known technique “weighting of items”. On a schedule of 2,500 tasks with some 600 different resources, it is not realistic to proceed by allocating the elementary resources on the elementary tasks of the schedule. This is why the 3D project management method recommends an approach “Top-Down” for the weighting of the tasks of the schedule, rather as the traditional approach “Bottom-up”, which does not work in practice on big projects, so much there are data to manage.
And the weight of each schedule’s task has 3 dimensions also!
The Zones were calibrated by to the number of hours necessary to carry out each room, and for the Products and the Activities one applied the same principle as for the durations. One applied the “technical” weighting on this project, and the result was a number of hours per schedule's task.
Finally, one obtained with PRIMAVERA P6 a planning system allowing to consider periodically the workload to come in men.hours, and thus to obtain a vision of the workload versus resources - what met the need perfectly.