The Work Package
During the process of creating a Work Breakdown Structure (WBS) you want to keep a “blind eye” toward project activities. Only after the WBS is thoroughly decomposed, do you consider the activities or efforts required to produce those WBS elements. Let’s take a closer look at this.
One of the seven habits in Stephen Covey’s classic “The Seven Habits of Highly Effective People”, is to begin with the end in mind. Good schedulers adhere to this principle by first creating a WBS of the project. The WBS is a hierarchical decomposition of all the project’s deliverables, i.e. the product or service that the project is producing.
Most scheduling guidelines require the existence of a WBS, so it is important to include a WBS in your schedule. And the WBS is a very helpful tool for organizing the products of the project. Note that the WBS is organized around primary products of the project and not the work required to produce these products
In the WBS the project is decomposed into increasingly smaller systems, components, and parts. The question at this juncture then becomes how far down does the scheduler decompose the project’s products into WBS elements? Or when does the scheduler know that the product or service the project is producing has been sufficiently decomposed into smaller elements?
The answer is when the scheduler has reached the work package level. In fact, the work package is the work defined at the lowest level of the WBS for which cost and duration may be estimated and managed. So, when you can define the duration and cost of efforts required to produce the deliverable you have reached an appropriate level of decomposition in your WBS. This is where you can focus in on the schedule’s required activities.
Again, activities are the efforts or work required to produce the deliverables or WBS elements. The required activities together with the deliverable or WBS element make up the work package. And a well-defined work package identifies these tasks that must be performed in order to deliver the work package.
This article discusses the work package and its placement in relation to the WBS.
So, the work package is the smallest component of deliverable and lowest level of the WBS. The work package cannot be decomposed into a smaller or lower level deliverable. It, again, denotes the lowest level of the WBS. Let’s investigate this with a real-life construction project.
Figure 1 displays an example WBS for the repair and improvement of an underground pipe system. In this WBS we have a site survey WBS element. The question at hand is, do I stop the WBS element decomposition at site survey or do I go further down and decompose this deliverable into mechanical lines site survey and electrical lines site survey?
Well, I estimated that it would only take a few hours to comprehensively complete the site survey for entire construction site, so it did not make sense to divide site survey into the further granularity of mechanical lines and electrical lines. So, I stopped at the site survey WBS element and made site survey the work package at this WBS element.
Continuing however, there was a different story for the safety or safety management WBS element, Figure 1. This time it made sense to further decompose this WBS element into safety plan and safety training. You must have an approved safety plan and you must train the team members working on the construction project.
In this situation you have a safety plan work package and a safety training work package. Each of these work packages contains one deliverable, and both work packages have work that comes with reliably estimated duration and cost.
A major required effort on this project, Figure 1, was excavation to expose the buried piping. For this effort we are essentially digging a trench. So, it appears to make sense to stop the WBS decomposition at excavation. That is, until we dig the trench below 6-feet when safety becomes an issue. And we must construct shoring to protect the construction workers in the trench helping the excavation process.
Once again it is best to further decompose the WBS element. The result is a trench work package and the sibling work package shoring. And, again, both work packages have a well estimated cost loading.
After repair of the piping, we come to quality assurance, Figure 1, which appears somewhat esoteric. And it is, until we further decompose this WBS element into a quality assurance report WBS element and an inspection WBS element.
Then at this level we can define the respective quality assurance report work package and inspection work package. The report work package is both the quality assurance report deliverable and the required effort of the planner estimator to write the report.
The inspection is the deliverable for the final certification of the project. The inspection work package consists of both the certification deliverable and the effort of the planner estimator, foreman, and government contracting officer to provide the final overarching inspection of the construction.
Had we stopped at quality assurance we would have been left with a rather nebulous WBS element, whose duration and cost are difficult to estimate. Further decomposition of quality assurance brought additional clarity and set our feet on solid ground where we have two clearly defined work packages, quality assurance report and inspection.
So, perhaps it is not quite appropriate to completely ignore activities or efforts when you create the WBS of the project. Yes, the WBS is a product-oriented break down of the project deliverables. But you must consider duration and cost estimating of activities to know when you have reached a final lowest level of decomposing project deliverables.
Again, this is the work package level of the WBS. The work package is thus a concrete or well estimated effort that produces a deliverable. And its placement is most suitable to appear at the lowest levels of the WBS.