Appendix D

Bicycle Work Breakdown Structure (WBS) Example

D.1 Overview

In Chapter 3, Work Breakdown Structure (WBS) “use-related characteristics” were described. These are WBS characteristics that vary from one project to another so that the WBS better satisfies the requirements of a specific project, industry or environment.

Consistent with this principle, a WBS can be represented in a variety of ways in order to achieve a specific purpose in a specific situation. A single WBS may also be represented in more than one way in various situations on a given project. This appendix illustrates a number of formats that are found in common practice today. All of these representations, as well as others not included here, may be used to detail the scope of a specific project. To allow the reader to focus on the differences among the various representations, a single WBS will be used to illustrate each format.

To help simplify the comparison of these WBS formats, we have chosen the bicycle project example described in the text of the practice standard.

D.2 Outline View

A very common representation of the WBS is the Outline View in which each level of the WBS is shown by the level of indentation and is accompanied by an alphanumeric outline code, or numbering scheme. Outline views are readily developed using a number of common tools, including word processors and spreadsheets

1 Bicycle

1.1 Frame Set

1.1.1 Frame

1.1.2 Handlebar

1.1.3 Fork

1.1.4 Seat

1.2 Crank Set

1.3 Wheels

1.3.1 Front Wheel

1.3.2 Rear Wheel

1.4 Braking System

1.5 Shifting System

1.6 Integration

1.6.1 Concept

1.6.2 Design

1.6.3 Assembly

1.6.4 Testing

1.6.4.1 Component Test

1.6.4.2 Product Test

1.6.4.3 Customer Test

1.7 Project Management

For some purposes, the outline view might not use indentation, but simply show the hierarchical structure through the numbering scheme:

Table D-1. Hierarchical Structure

Eliminating indentation may make the WBS less intuitive for the reader, but may save space in certain documents.

D.3 Tabular View

Another common representation of a WBS is the Tabular View in which the hierarchical structure is represented through columns in a table. Tabular views are common in situations where it may be difficult to use a more graphical format, such as text document with limited formatting capability.

A different type of tabular structure is sometimes encountered in government publications. Such displays often include additional information such as cost accounting codes, organizational elements responsible for the WBS element, etc. It may be difficult to display more than a few levels of a WBS using this format.

D.4 Tree Structure View

One of the most common ways to represent a WBS is the graphic Tree Structure, or “Organizational Chart” structure in which each “child” element is shown as a box with a line connecting it to the “parent” element of which it is a component. This representation makes very explicit the way in which the project and the subordinate components are hierarchically decomposed into smaller and smaller elements. The most common version of the tree structure places the project at the top level with successive levels of decomposition below.

Alternatively, the orientation of the WBS Tree Structure view may be modified. In these cases, the project may be placed on the left with lower levels of decomposition moving to the right. For some purposes a landscape orientation may be useful. Below are two similar examples of this.

Or in other cases, a horizontal portrait orientation may be more useful.

An increasingly popular format is the Centralized Tree Structure. This type of format is produced by software that is used for facilitating development of the WBS through real time group interactions. Below are two examples of the centralized tree structure WBS.

D.5 Enhanced Uses of the WBS

By including information in the WBS in addition to the core WBS Element Name and WBS Code, the WBS can become the explicit means for integrating other project management processes with scope.

One example of such enhanced use is the WBS Dictionary which adds a detailed definition of each WBS Element. The WBS Dictionary may also include key cost control and resource assignment information, as in the following example. Note that the cost control number column is left blank, which can be a placeholder for the information once it is made available when the order is taken.

There may also be occasions when a WBS may contain less information than is standard usage. For example, for communication of the WBS to a non-technical audience such as the customer or senior management, it may enhance the communication if the code numbers that normally accompany the WBS elements are suppressed. This is acceptable because it addresses the needs of a specific situation.

D.6 WBS Code Numbers

In the examples above, the WBS code uses a numbering scheme consisting of Arabic numbers separated by periods. This allows for easy and systematic expansion of the WBS as additional elements are added. In other cases, the WBS code might use a different alphanumeric system, for example, a combination of Roman numerals, letters and Arabic numbers. This particular system does not lend itself to systematic expansion as a purely numeric code. In some cases, the numbering scheme may be defined by the organization in such away as to permit coordination across projects and enable program level cost control. The WBS Code serves as a unique identification number.

I Bicycle

I.A Frame Set

I.A.1 Frame

I.A.2 Handlebar

I.A.3 Fork

I.A.4 Seat

I.B Crank Set

I.C Wheel

I.C.1 Front Wheel

I.C.2 Rear Wheel

I.D Braking System

I.E Shifting System

I.F Integration

I.F.1 Concept

I.F.2 Design

I.F.3 Assembly

I.F.4 Testing

I.F.4.1 Component Test

I.F.4.2 Product Test

I.F.4.3 Customer Test

I.G Project Management

The WBS examples in this appendix are illustrative only and are intended to provide guidance to the reader. No claim of completeness is made. All examples reflect the quality principles expressed in this Practice Standard. As expressed in the PMBOK® Guide—Third Edition “the project management team is responsible for determining what is appropriate for any given project” (Project Management Institute 2004).