Progressive Elaboration and The Project Management Plan in the PMBOK 4th Edition
During last weeks PMBOK course here at Tracasa we covered Chapter 4 and there was a lot of confusion about the process output, Project Management Plan Updates. One of the main reasons for the confusion is that the DFD diagrams show the Plan Updates flowing back to the Develop Project Management Plan process. At first reading, this may seem appropriate but it contradicts a popular interpretation of the integration knowledge area and progressive elaboration of the Project management plan. This interpretation is that you only carry out the process develop project management plan only once per phase iteration. That is to say that the full PDCA cycle is only carried out once per iteration and that the plan updates, which may or may not be subject to change control, update the project management plan directly or in some cases through the directing and executing process.
Several arguments can be made for this way of thinking.
- The develop project management plan does not a have a plan updates input
- The work of integrating input from the individual knowledge areas which is carried out in develop project management plan process has already been carried out in integrated change control process and hence there would seemingly be redundant work.
An explicit presentation of this view has been made by Muhamed Abdomerovic (thanks for the link to Alberto Goicoechea). We contacted Muhamed and asked if he had gotten input from PMI or PMBOK authors on his conclusion that the DFD flow for Project Plan updates is indeed incorrect in the PMBOK. He tells us that he has not.
We also searched for any other references to this error in the DFD diagrams but so far have not found any.
The more high level view and one more consistent with making the standard more flexible would be that the Develop Project Management Plan can in fact be repeated as needed even in a single phase but it must at least be performed once. Since the PMI view would most likely be that this first use of the process is the most important one, it is this iteration of the inputs and outputs that are focused on and hence diagrammed in the book. If indeed project management plan changes are made they may require re-planning to some degree and this reflects more of a PDCA structure. The Integrated change control would represent the Act phase of the PDCA cycle and the develop project management plan in the follow on cycles of the plan phase.
Which is better? The answer as usual is that it probably depends. In many ways this type of process "short circuit" can be found in other best practices frameworks such as ITIL where some short cuts are taken in the name of efficiency such as the support-operations bridge configuration.
In many real situations there are cases where it may seem like a too costly of an exercise to enter the develop project management plan process for every plan update. On the other hand some plan updates may just be to big and may require it. Maybe this signals a good time to think about using multiple phases in your project.
