Work Breakdown Structure (WBS)

The work breakdown structure (WBS) is the most important issue in the project plan. The WBS defines the work that has to be done to complete the project. Moreover, the WBS can help determine the cost of the project and its schedule.

As commonly used in projects, as in Figure (4.2), a project consists of three pipelines: a water pipeline to transport water, a pipeline for crude oil production from the plant to storage, and a gas pipeline to transport gas from the production plant to the treatment plant.

The structure of work activities is divided by the project into lev­els. The first level defines the main stages of the project. Regarding levels two and level three, three pipelines are envisioned. Concrete work includes setting the concrete base, as well as electrical work.

The second level in the WBS will be focus in the Figure (4.2) on stages of the pipeline work. At that level, there will be more than one stage — design drawings must be produced, and appropriate further calculations performed.

Figure 4.2 Presents work break down structure (WBS).

Level three in this example focuses on the design phase and will be divided for the design of the gas pipeline and oil and water.

In the fourth level, we design a gas pipeline by performing hydraulic design and pipe stress analysis to choose the thickness of the pipe and support locations and to ensure that the subsequent stage is the selection of the required valves. In some projects, it may require several stages depending on the nature of each project.

We note, each stage in each level code for ease of use later. The WBS can be completed at any level of description. The WBS does not explain the relations between the activities nor does it show the time or the time period for any activity.

In summary, the WBS is implemented by following the steps as shown in Table (4.1).

Table 4.1 Work breakdown structure


The WBS is a high-level breakdown of work scope, a list of main project deliverables, and can be broken down by materials, contracts, area, or defined work packages.


The WBS is used to break jobs into linked tasks. It is the basis for the estimate, the cost report, and the execution plan. Having a common format across all elements of the project results in simpler cost tracking and forecasting.


The project team should brainstorm the best way to control and implement the project by assessing the project execution methodology together with the commissioning sequence.


The WBS should be included in the project execution plan, early in the select phase, and revised throughout to define and execute.


Project Leader, Planner, SPA, Construction Engineer, Commissioning Engineer, Estimator

After you have selected the main stages and WBS, the next step is to develop a rough period of time on the schedule, but there is an important step prior to that, which is to define responsibilities.