Finding Dependencies

04 December, 2014

While practicing Project Managers often curse the constraints they are put under, the sad fact is that, without constraints, we would have no need for Project Managers. Even if you are not a Project Manager, you will have had to manage projects in your own life. Weddings, holidays, even job hunts all involve planning the work and then working the plan. So even outside of the office, we will have to work within the constraints provided.

Although the Guide to the Project Management Body of Knowledge (PMBOK® Guide) never talks about the Triple Constraint, it is a staple concept in any project management course, including PMP® exam preparation ones. So we have to learn how to deal with tight schedules, miserly budgets and stringent quality demands.

But even within our schedules, we are faced with constraints. Activities often depend on other work being done, so we are not free to compress schedules as much as we would like. Every time we have an activity to schedule, the first question we need to ask, whether we are a PMP® certified Project Manager or otherwise, is what needs to be in place before we can start this task? For instance, I cannot paint a wall until it is built. Similarly, I cannot replace a faulty component until I have removed the original, defective component. This is a useful exercise because you often find that this activity has been placed after another by accident. If the preceding activities in your network diagram or Gantt chart are not essential for this particular activity to start, remove the dependency.

Another question to ask is what other activities can start at the same time? The standard example here also comes from house building: once the walls are plastered, every room in the house can be painted. There is a temptation to sequence the rooms to reflect the reality that you have only one painter on the job. However, you need to begin by determining what could be done if you had infinite resources. This will highlight areas where additional staff or facilities could be brought to bear to get things done faster (remember the term for this from your PMP® training? That is right: “crashing”).

Something that gets forgotten, especially on ad-hoc schedules, is the need to include sign-offs and approvals. Does this activity need some sort of formal sign-off before it may commence? A good example is building again. None of the construction activities can commence without planning permission. So you need to ensure that this sign-off happens before you start. The PMPs® among you will remember the concept of Phase Gates – points in the project where senior management have to decide if the project is worth continuing with. This is a similar idea. Whether approval is formal or informal, this must be noted in the schedule, perhaps by using a milestone marker.

Now that you are sure that everything necessary (and nothing that is unnecessary) precedes this activity, let us look at the consequences of doing the activity itself. What are the completion criteria for this piece of work? Agile Project Managers who are experienced with Scrum project management will be familiar with the Definition of Done. These are the tasks needed to be performed before the activity is complete. This is a really useful exercise for the Project Manager as it allows the activity to be reviewed before declaring it finished.

Another useful thing to consider is if any decision points are required within the activity? This might reveal other dependencies. For instance, we might have everything ready for the painters to go to work, but no one has picked out the colours to be used. If you are preparing a dinner party, you need to know if any of the guests are vegetarian or otherwise constrained (that word again) in their choices.

Events within the activity can dictate what happens next. For instance, we might attempt a Do-It-Yourself activity and make a mess of it, implying that the next activity will be contracting out the work to someone else. This will be highlighted in the Project Plan as a risk and the outsourcing step is a contingency response plan. Network diagrams do not allow us to include decision points (unlike flowcharts), so we will not be able to choose between subsequent activities based on their outcomes. But this is not an issue at this point. Remember the term for what we are doing from your PMP® training? It is called the Precedence Diagramming Method, so we want to note the dependencies, not the workflow as such. So we might place several activities behind another but only one of them will be executed, depending on the outcome of the predecessor activity.

The final thing to consider is whether we need our activity signed off before it is considered finished. This could suggest a milestone marker after our activity indicating a key event in the project.

The network diagram is on output of the Sequence Activities project management process. It needs to reflect the dependencies between activities. It does not need to include known constraints yet. We have the Estimate Activity Resources and Estimate Activity Durations to go yet before building up the schedule itself. These will put timeframes and assign actual team members to the work. These will limit what can be done but having a good precedence diagram will allow us justify additional resources by simply knowing what we can use them for.

Velopi’s PMP® exam preparation courses cover the Project Time Management knowledge area and rest of the material you need to obtain PMP® certification. Please visit our training page or contact us directly for more details.

By Velopi Seamus Collins

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