In any construction project, the various activities that make up the project have to make up the project have to be clearly identified. The process of breaking the project into easily identifiable major system, their sub-systems and discrete activities is called as work breakdown structure.

The major project is first identified in terms of its end items, then split into system, sub system their component and elements.

Hence work breakdown structure is a device that identifies the functional elements of project and their inter-relationship. When the project is split up in this way into its various functional elements, this will not only help in preparing the network for the project but also in planning and scheduling the activity.