Work Breakdown Structure

Abstract

It is beyond any reasonable doubt that the Work Breakdown Structure (WBS) is the foundation of planning, estimating, scheduling, and monitoring any kind of activities. With its contribution an outline of common reference for all schedules and better estimates is ensured. A Work Breakdown Structure (WBS) is the process of subdividing project deliverables and project work into smaller, more manageable components. More specifically, it is a hierarchical decomposition of the total scope of work to be carried out by the project team to accomplish the project objectives and create the required deliverables.

The purpose of this wiki-article is not only to thoroughly describe the capabilities and restrains of this method but also to provide guidance concerning the techniques that can be used for the effective implementation of project Work Breakdown Structures.

Introduction

Historical Retrospection

The first forms of Work Breakdown Structure (WBS) were developed by the U.S. Department of Defense with a view to improving their missile systems at mid-1960s. The fundamental concept of the WBS and the practices around its use were initially established by the U.S. Department of Defense (DoD) and National Aeronautics and Space Administration (NASA) for the purpose of planning and regulating broad procurement projects whose primary objective was the development and delivery of weapons and space systems respectively. These projects generally involved a lot of industrial contractors each with responsibility for independent segments of the system and were also managed by a central administrative office. In this environment, the WBS was used to “…ensure that the total project is fully planned and that all derivative plans contribute directly to the desired objectives” (NASA, 1962).

Work Breakdown Structure Definition

A project is made more manageable by breaking it down into individual components that together are known as a Work Breakdown Structure or WBS. Such a structure defines unique work elements that can be arranged and completed in the order defined by the network diagram: sequentially, in parallel, or in the specific order necessary to accomplish the project outcomes. Furthermore, it facilitates other project management processes such as estimating, scheduling, resource allocation, risk analysis, and measurement and control of the project. This tool is a representation of a clear description of the project’s deliverables and scope. In addition, the WBS method is not a description of a process or schedule that defines how or when the deliverables will be produced, but rather is specifically limited to describing and detailing the project’s outcome or scope. Moreover, it organizes and defines the total scope of the project, and represents the work specified in the current approved project scope statement. The planned work is contained within the lowest level of WBS components, which are called work packages. A work package can be used to group the activities where work is scheduled and estimated, monitored, and controlled. In the context of the WBS, work refers to work products or deliverables that are the result of activity and not to the activity itself.