Creating a well-organized Work Breakdown Structure (WBS) is always on my list of “critical few” project management best practice areas. The WBS is utilized to effectively define the scope of the project, decomposing the work down into components that can be estimated, scheduled, and tracked/controlled throughout the project life cycle. The WBS makes the scope of the project actionable in the form of a deliverable oriented and hierarchical view of the work. The WBS defines the scope of the project down to the lowest level deliverables called work packages.

One of the most common questions I get when discussing the WBS with project teams is, “What is the best way to organize the project deliverables?” A lot of people think the answer must be obvious, because it does not seem to get discussed much by the team when the WBS takes its initial shape / form. It is not at all a stupid question. There are two very different ways that team members think about the project. One way of thinking about the project is focused on the product that is being created, and the other perspective is based upon how the project work will be completed. Selecting one school of thought over the other will drive a totally different end result in terms of the organization of the WBS. As the project manager, you have to live with the organization of your WBS throughout the project life cycle (it drives the organization of the project schedule, as well as the monitoring / controlling processes), therefore you want to be sure you have purposefully selected an organization approach that works for the project team.

Product Based WBS Organization

For those of us with experience in a manufacturing environment, you are familiar with the concept of the bill of material. The bill of material describes how to build a product from the end product down to the lowest level parts or components. The bill of material is utilized to manage building products in a repeatable, efficient, and cost effective manner (automated utilizing an ERP system). When designing or developing a new product, the bill of material is a logical manner to organize the work that needs to be completed. For product development type projects, organizing the WBS in this manner helps the team think about and visualize whether or not they have effectively accounted for and planned all aspects of the product. This approach also provides an understanding of how different aspects of the product are coming together as the product development effort progresses.

Project Based WBS Organization

As a project manager, I generally think about the project effort in terms of how the work is going to be completed (based upon the timing and dependencies associated with deliverables). With this approach the work is grouped into work streams (sub-projects), and project phases (defined with major milestones). As you get into lower levels of the WBS the organization of deliverables is based upon the different components of the project or product. This approach allows the project manager to update the project “from top to bottom” as the project progresses (assuming the project progresses in pretty much the same manner as it was planned).

What is the Best Fit for My Project?

There are good reasons to organize your WBS from both the product and project perspective. Below are several factors to take into consideration when you are working with your team to determine the best approach for organizing your WBS.

• Standalone vs. Dependent Work Efforts – Where are the majority of the dependencies and interrelationships within the separate work efforts? Are the dependencies more focused on the product components or the phases of the project? Are the project milestones tied to the product components or gates in the project life cycle? It is much easier to manage dependencies in a vertical manner within a single work stream, rather than in a horizontal manner across multiple work streams.
• Wide vs. Deep – Based upon my experience, it is much easier to manage a project that has a WBS that is deeper (vertical) than it is wide (horizontal). Part of this preference goes back to the fact that it is easier to manage dependencies within a single work stream (vs. across work streams). However, I also find that it is easier to manage and measure progress of the overall project (solution) if there are fewer separate work streams that link directly to the highest level of the WBS (the over solution / project summary). For example, if there are 15 major product components associated with your project, with significant dependencies across the components, you should have a good case for organizing the WBS around the project life cycle.
  
• Who Cares? – Who are going to be the major consumers of the information maintained within the WBS and the project schedule? Is the effort more product or project focused? If it is a very product focused effort, largely comprised of a team of engineers, you may be fighting an uphill battle to suggest that the WBS should be organized based upon the project phases.
• What Does Progress Look Like? – How will you be receiving updates on project progress? Will progress updates be organized around separate product related work efforts, or based upon the project phases and upcoming project milestones? Again, the answer to these questions will be largely dependent upon the composition and focus of your project team.
  
• Iterative Implications – When the team makes the decision to deliver the project in an iterative manner, they are making the decision that the WBS needs to be organized around the iterations. Iterations are time based, and therefore the WBS takes on a project based organization structure (with the project phases being the individual iterations and milestones for deployments).
  
• Either approach will work – As you can tell from my analysis above, I am a project manager and obviously favor one approach over the other. The bottom line is, either approach can work for you and the project team. I can honestly say that some of my most successful project were managed with a product based WBS. In some cases additional steps are required in the WBS definition, and schedule set-up to provide views of the schedule / status from both a product and project perspective. This can be accomplished in MS Project by creating custom fields and special views (using sort and filter functions with the custom fields).