WBS: The Base for All Plans

Defining the WBS

Every project manager uses Work Breakdown Structures (WBS), right? On all projects? And are the Work Breakdown Structures as strong as they could be?

Most times, when we are asked to come in to help out on a project part way through, we have to look pretty hard to find a WBS at all, never mind a good one. We usually are handed a schedule covering some of the work, reflecting phases or activities in a loose hierarchy.

So what is wrong with listing the primary tasks and activities? Well, if the project comes off to the satisfaction of everyone, then nothing is wrong. Many projects have been successful without any sort of written plan or schedule at all, so obviously we can do without a WBS.

But usually someone wants better predictability, better insight into performance, better communications, better use of resources, better results, better return on investment, or just better control. A good WBS can help achieve these.

Making the Base Stronger

The Work Breakdown Structure is the basis of the contract between the project manager and the sponsoring organization. It is the tool that defines the scope or contents or deliverables of the project, and scope drives everything. While problems with schedule, cost, or resources may be self-contained, scope problems usually lead to new problems with cost, schedule, resources, client relationships, team morale, contracts, and profitability. So it makes sense to create the strongest WBS possible, right from the beginning.

1. The first point is to ensure that you have a WBS. Just do it. Every time. Like brushing your teeth or putting on your seatbelt, it will pay off when you most need it. And like seatbelts, if you haven't used one and get into trouble, it will be too late.

2. The second recommendation is to make the WBS comprehensive. Aim to make the WBS exhaustive in its coverage: including everything that will be delivered and nothing that will not be delivered. In this way, no work will be done "off the page" or "under the table" and nothing on the table will be missed. This is a great way to build everyone's confidence that the project is thoroughly understood.

3. The next recommendation is to make the WBS product-oriented. Yes, many standards allow for a process-oriented WBS. And many methodologies instruct the PM to "list the tasks to be performed in a hierarchical work breakdown structure, showing phases..." but this approach is weaker. The project should be about results - the customer wants results from the contractor; the manager wants results from the team; the delivery organization needs successful business results. A product-oriented WBS supports the focus on results and deliverables. Every WBS element becomes a target to be completed and every scope discussion will be about results.

Now, in some cases, the customer is paying for services and no direct results are expected. The US Federal Acquisition Regulations (FAR) distinguishes between contracting for services and for supplies (or products): ‘"Service contract" means a contract that directly engages the time and effort of a contractor whose primary purpose is to perform an identifiable task rather than to furnish an end item of supply.' For time and effort elements within the WBS, activity- or process-orientation is appropriate.

4. Finally, build a good hierarchy. The high level elements will provide logical groupings of deliverables and products; the organization and architecture of the project will be apparent. As one drills into the hierarchy of the WBS, one sees more detail and more specific and concrete deliverables. A good hierarchy will allow planning to proceed in stages, with high level place-holders where only preliminary planning has been completed, and detailed WBS elements at a low level where more thorough planning has been performed.

Remember the rules of a good hierarchy, too: every element appears only once; elements have only one parent; and the sum of all child elements is the parent element.

Why All This Bother?

The reason for this is clarity. Every planning decision - tasks to perform, durations to allocate, resources to use, budget to reserve, tests to execute - depends on the scope, and everyone needing clarification on scope should be able to get that clarity by referring to the WBS. Now, if you are not seeking clarity, then you may wish to ignore this advice.

Many years ago the world's biggest customer - the US Government - got fed up with projects that ran out of control as a result of elastic scope definitions. They developed the granddaddy Standard for Work Breakdown Structures (MIL-STD-881-B), subsequently revised and updated as the Department Of Defense Handbook On Work Breakdown Structures (MIL-HDBK-881A). It is available from the US Defense Logistics Agency online or for download.

Most US contractors now use this standard as a matter of course, which has probably contributed to the higher average level of PM Maturity that we have observed south of the 49th parallel. This is a best practice; let's use it.

Alan R. Boyce B.A.Sc., MBA, P. Eng., PMP, CMC