Work Breakdown Structure in Project Management

Abstract

Project Management is often a complex process involving Stakeholders, Teams, Development Approaches, Planning, Project Work, Delivery, Measurement, and Uncertainty. As part of Planning and Delivery it is important to define the Scope and Requirements in order to break down the complex tasks into manageable sub-tasks of the whole project (PMBOK; Seventh Edition, 2021, p. 81). Therefore, in this Wiki article, the Work Breakdown Structure (WBS) will be presented as a Project Management method used to reduce the complexity of a project by delimiting the whole project plan into manageable sub-tasks. This Wiki article will further cover context and history of WBS along with explanation on how to use it in Project management and what are the principles, advantages and limitations of this method. Since WBS is very flexible and easily applicable tool, the article will focus on most popular ways of application specifically used in Projects.

Context and Historical Applications

Historically, the Work Breakdown Structure method was inspired by Program Evaluation and Review Technique (PERT) used by United States Department of Defense (DoD). In 1968, along with aerospace industry and National Aeronautics and Space Agency(NASA) DoD has published a "Work Breakdown Structures for Defense Materiel Items" (MIL-STD-881). Similarly, NASA has adopted WBS and has a handbook of its own. https://ntrs.nasa.gov/citations/20180000844 WBS in both organisations are used for Programs, Products and Projects.

WBS Terminology, Principles and Framework

Before diving into the framework of Work Breakdown Structure and its applications it is important to understand the main terms and princples. Therefore, this section will cover main terms of WBS along with explanations and principles with their impact to the use of method.

Terminology

WBS Levels - A visual and coded arrangement or configuration of a WBS which enables the hierarchy of a projects to deliverables and deliverables to work packages and tasks. (Nasa)

Deliverable - Ussually expressed in nouns/adjetives, the deliverables are the work products of the project. They are aimed to describe "what" of a project with an intention to express results and not only actions. They are usually visualised as a separate box in WSB template and have a specific code assigned to it.

Work Package - The lowest level of a deliverable which contains a clear identification of tasks, activitess and milestones that have to be delivered in order to fulfill the deliverable.

Principles

Decomposition - As indicated by the naming, this method relies on Breakdown principle often called Decomposition. The main idea of this is that the project has to be decomposed into a delivarables with a level of detail which would precielly capture the whole scope of the project and at the same time maintain that level of detail for effective communications, task divisions and control.

100% rule - Following the principle of Decomposition it is important to keep the scope of each deliverable in line with the whole project and its limitations. Therefore the 100% rule is essential when developing WBS and it states that each level of WBS decomposition has to make 100% of the work of its parent element. (pg 23 Norman).

Project Scope - Each deliverable and element of WBS has to be within project's scope and any tasks that do not belong to the project, should be left out.