The Project Schedule Part 3: Work Breakdown Structure (WBS)


A Work Breakdown Structure (aka WBS) takes high level deliverables and breaks them down into lower-level activities suitable for assigning, managing and scheduling work. Creating a WBS is the first step in creating a schedule.

To build a project schedule, you must first define all of the activities that are part of the schedule. If you have created a Project Charter and a Project Plan, you have rich sources of information with which to define the deliverables and the activities needed to produce them.

The Project Charter contains the Project Objectives, which are products, services or results that the project will produce and will survive after the project is over. These are the ultimate deliverables of the project. The Business Objectives contain “Measures of Success” which may require the project to build measurement tools and processes. The Scope section contains high-level activities which can be broken down to smaller pieces for scheduling.

The Project Plan contains the “hows” of the project and most or all of the key project activities were defined there. As the Project Manager, you will need to decide at what level you will define the activities for scheduling purposes. As I mentioned in an earlier post, I am not a fan of Project Schedule’s that contain a large amount of activities as you will wind up putting more effort into schedule maintenance than the benefits you derive.

One common way to define the activities (create a WBS) is to start with the project deliverables and work backwards from there, asking the questions “What inputs are needed for this activity?” and “What activity creates each input?”. For example, for the Requirements Document deliverable, you need final approval. To get final approval, you need to conduct a review meeting. To conduct a review meeting, you need to schedule it. To schedule it, you need a draft document. To get a draft document, you need to write it. To write it, you need to schedule and conduct requirements gathering meetings. And so on until you reach the very first activity which either needs no inputs or the inputs have already been created.

If the deliverable is simple enough you can start from first activity and drill forward. Either method should work. For activities that are not yet well understood or defined, you can define high-level placeholders in the schedule and add the activities needed to obtain the understanding.

Once you have all of the activities, you will work on assigning the resources to the activities and defining the dependencies between activities. I will cover these topics in the upcoming posts.