Q001: How can we discover the internal structure of the project management process?
We can regard the project management sub processes as procedures in the sense of computer science: they take some parameters as input, compute some results - sometimes by calling other procedures or (sub) procedures - and generate respectively return their output. A process is a set of procedures. The internal structure of this process is the sequence of the used procedures constituted by the generated input and output: a procedure is a successor of another procedure, if it takes the output of the preceding procedure as its own input and computes its output on the base of this input.
On the base of this principle we can specify three rules for discovering the internal structure of the project management process presented in the PMBOK3:
- Each successor (sub-)process is connected to the preceding (sub-)process by a specific directed acyclic path of other sub-processes. Each (sub-)process of this path takes the output of the preceding (sub)process as input and computes its own output. These links constitute the main structure of the whole project management process as directed graph.
- Some of the (sub-)processes not only produce new output documents, but also update already existing documents which already have been generated and returned by other procedures. These updated documents can either explicitely been delivered into the updating (sub-)process as input parameters (in the sense of 'call by reference'). Or they can be implicitely introduced into the updating (sub-)processas as permantely reachable documents (in the sense of 'global variables'). If such a document / output is updated, the results of those processes is no longer nescessarily valid, which have been computed on the base of the updated document. Hence those (sub-)processes must be repeated which operate / compute their output on the base of the updated document. And therefore a (sub-)process, which updates an existing document, constitutes a link to those of his preceding procedures which takes this (now updated) document as input. In this manner loops are introduced into the project mangement process: updates of existing documents constitute the project management process as cyclic directed graph.
- In the project management process there exists a specific type of documents which formally act as output / input and constitute strict predecessor successor sequences but which constitute backward links by their sense and content: they are called the 'requested changes'. Requested changes are produced by many (sub-)procedures. They are taken as input by other processes which generated 'approved change requests'. And approved change requests become input of other (sub-)processes which directly and / or indirectly generate change requests again. For discovering an acyclic directed graph as kernel of the project management process structure we can ignore these input parameters, we ignore their successor building potential. And then we add backwards loops from those processes which generated approved change requests to those processes which take approved requests as input.