(WBS) - Work Breakdown Structure

The WBS (work breakdown structure) is a process used in project management to identify the scope of a project and all the associated tasks that must be done to complete the project as defined. For this purpose, a results-oriented hierarchical decomposition of the work is carried out. This technology not only makes the work more accessible and manageable. It also enables the monitoring of different processes of a project, the estimation of costs and schedules and helps with team building. This led to WBS becoming one of the most important project management tools.

In the following, the author presents the different structuring techniques of a work breakdown structure. Furthermore, he describes the process of creating a work breakdown structure, the different forms of presentation as well as the advantages and limitations of a work breakdown structure and will illustrate these with examples.

Backgroud

As part of the U.S. Navy's fleet ballistic missile program (Polaris), the Program Evaluation and Review Technique (PERT) program was established in 1957 to address backlogs in planning. The program was designed to find a solution that would generate all the necessary tasks and efforts for the project based on its outcome. In 1962, the Department of Defense (DOD) and NASA published the first description of the work breakdown structure (WBS) with PERT as a model and later adopted it as the standard for the entire DOD product line. However, the first naming took place only in 1968. Beginning in 1987, the work breakdown structure (WBS) was first introduced by the Project Management Institute (PMI) with the PMBOK as a standard procedure for non-military operations, e.g., for applications in companies and other organizations and has been further developed by means of the introduction of a project charter since 1999.

Fundamentals of the WBS

• Packages
• Control accounts
• Levels & coding
• WBS Dictionary
• 100% Rule

Diffrent Type-structures

• MECE Structure

Deliverable-Based WBS

• Based on tangible items

Phase-Based WBS

• Build around the project life cycle phases

System/Subsystem

• Build arround systems and subsystems that compose those systems

Mixed or Hybrid

• Incorporates two or more of the approaches mentioned above

Types of WBS Charts

• WBS List
• WBS Tree Diagram
• Gantt Chart

How to Create a Work Breakdown

• Top-down
• Bottom-up
• Yo-Yo approach

Benefits and limitation of WBS

Benefits

• Detailed illustration of scope
• Monitor progress
• Cost and schedule estimates
• Build project teams