Dear PM Advisor. June 3, 2013

Dear PM Advisor, How do I show parallel activities under one Deliverable in my Work Breakdown Structure? And what about dependent variables where some work only happens if A occurs and other work happens if B occurs? 

Divided in Delaware.

Dear Divided,

A lot of people, when first building a WBS and placing Post-its on a wall representing work, are tempted to turn it into a flow chart, simply because they've done this before. That is NOT what a Work Breakdown Structure is. The WBS is a breakdown of WORK required to complete the project. There is no element of TIME in the structure.

That being said, most people, when building a WBS, will think chronologically. What is the first activity needed to complete this deliverable? What is the second? And so on down the line. When two activities occur in parallel, they want to draw them in parallel. Please don't do that.

For one thing, the structure of WBS won't support that. Deliverables are placed next to each other and the activities line up underneath them. If you try to split them, you'll have to move the Deliverables around. But it's not needed here. When you build your schedule, then the time comes to indicate the timing of the activities. So load up the activities under each deliverable in roughly chronological order and parallel activities line up in a column. It's up to you if you want to put one set of activities under the other set or dovetail them. Either way, the schedule will sort it out.

Now, your second question deals with optional pathways, If-Then statements. Don't build these into your WBS. If you did, how would you show that in your schedule? There are more complex ways of showing loops like GERT but I don't recommend them for normal projects. Leave this technique to organizations like NASA.

Instead indicate the most likely scenario in your WBS and document the assumption and risk associated with this option. People reviewing your project plan may challenge your assumption and ask you to plan for the other option. That's OK. Remember, people approving your Project Plan are not just approving your cost and schedule, they are also approving the assumptions you are using to reach these major constraints.

Good luck,

PM Advisor

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