WBS Work Breakdown Structure (Work Breakdown Structure) is a planning and design tool for describing ideas. It can clearly express the interconnected structure of various projects, detail the work that must be completed to complete the project, and can also be submitted to Top management and the client report on project completion.
There is a saying in the circle of project managers: Without WBS, there is no project management. This shows the importance of WBS in project management. So, how to understand WBS specifically? And how to apply it?
WBS decomposition mainly has the following five steps
WBS consists of three key elements
① Work—a task that produces tangible results.
②Breakdown—a hierarchical structure of gradual subdivision and classification, which refers to decomposing major tasks into specific tasks, and then subdividing each task into many activities.
③ structure (structure) - organize each part according to a certain pattern. That is to say, no matter how many tasks and activities are decomposed into one task, these tasks and activities should be clearly structured, and there are certain internal connections between them. We must be well aware of this connection, only in this way can we complete our work efficiently.
Take, for example, the project "Put an Elephant in a Freezer."
In order to put an elephant into a refrigerator, we first need to manufacture a refrigerator that can hold a giant elephant. Now, the refrigerator manufacturing project is decomposed "based on the perspective of deliverables", and the first layer can be divided into a cabinet, a refrigeration system, and a control System, etc.; the second layer takes the box body as an example, which is divided into shell, liner, heat insulation material and box door. See the figure below for details.
From the perspective of the overall process of "putting elephants into refrigerators", the first layer can be decomposed into overall scheme design, refrigerator manufacturing, elephants into refrigerators, refrigerator transportation, etc. by adopting the "division method based on work process" decomposition; Layer subdivides the work of the first layer into the work content they contain, and the decomposition results are shown in the figure below.
Matters that need to be clarified in the process of WBS decomposition
① The decomposed activity structure is clear.
② Logically form a large activity.
③ Integrate all key factors.
④ Contains temporary milestones and monitoring points.
⑤ All activities are clearly defined.
Three commonly used decomposition methods for WBS
① Analogy method, that is, to construct the WBS of this project based on the WBS of a similar project.
②Top-down method, it is often regarded as a conventional method of constructing WBS, that is, starting from the largest unit of the project, and gradually decomposing them into multiple tasks at the next level. This process is to continuously increase the level and refine the tasks.
③Bottom-up method, that is, let the project team members determine the specific tasks related to the project as much as possible from the beginning, after listing the detailed task list, classify all the tasks, and then classify each specific task Integrate and summarize into an overall activity or the upper level content of WBS. The bottom-up approach is generally time-consuming, but it works especially well for WBS creation. Generally, such a decomposition method has higher requirements on the ability level of project team members.
Considerations for WBS Application
① The status and completion of each task can be quantified.
② Clearly define the start and end time of the task. Tasks are geared toward deliverables, not processes. Every task has a deliverable.
③ A task can only appear once in the WBS, and each task in the WBS generally has a specific person in charge.
④ The construction period is easy to estimate and within an acceptable period, and it is easy to estimate the cost. General definitions consider the 80-hour rule or the two-week rule.
⑤ Each task is independent and can be described.
⑥WBS must be consistent with the implementation process in the actual work.
⑦The project team members should be actively involved in creating the WBS to ensure the consistency of the WBS.
⑧Each WBS item must be documented to ensure an accurate understanding of the scope of work included and not included.
Ways of expressing WBS
There are two main ways of expressing WBS:
- Tree structure: a graphical view of the structure. (as in the Putting the Elephant in the Freezer project above)
Advantages: clear structure.
Disadvantages: Large projects are difficult to fully display. It is suitable for small projects, or the display of a fragment in a large project.
- Outline structure: similar to a book chapter table of contents. (See the figure below for the outline structure representation)
Advantages: It can fully display the scope of the entire project, and can form an enterprise standard WBS template. Suitable for all types of projects.
WBS is very important to project management. It is the basis of leveraging time, cost, quality and risk management. Learning to use WBS decomposition method can help us ensure the systematization and integrity of the project structure, make the image of the project transparent, and lay a solid foundation for the follow-up The work laid the foundation, and it is also a means of communication and coordination among various departments.
How WBS works in terms of progress management, risk management, and team management also requires each project manager to dig out and extract a way that suits him.