Assume someone is a project manager in a project that is trying to create a rather massive solution.
The project manager has to define a process on how the project will proceed. This involves dividing the work into tasks and subtasks and defining a causal relationship between the tasks (i.e. in what order they have to be done, what can be done concurrently, etc..)
What functions are most relevant / most heavily used dividing the job into tasks, subtasks and creating the process which binds the tasks together?
Now the project manager has to estimate how much time it takes to complete each task and subtask in order to calculate a time table and cost estimate for the project.
What functions are most relevant / most heavily used in estimating the time and work effort it takes to do a task?