The American University in Cairo
Engineering Department
Mechanical Engineering Unit
MENG 446 : Management of Engineering Projects
Dr. L.K. Gaafar
Joseph Kamal
Mohamed El Daour
Mohamed El Fatih
Sherif Masoud
Youssef Youssef
Work Breakdown Structure
Outline










Introduction
Origin of WBS
Definition
WBS Structure
Developing WBS
WBS Role
Applying WBS
Project Coding System
WBS Rules
Conclusion
Introduction

During the course of any project, numerous activities must
be completed by several individuals or organizations.

A key strategy of effective planning is to partition the
project into manageable chunks that can be individually
planned, estimated, and controlled.

Such division is done through the development of a work
breakdown structure (WBS).

The work breakdown structure is a graphical tool that
displays the project’s statement of work.
Origin of WBS

The WBS approach of the US Department of Defense’s
Cost/schedule Control System Criteria (C/CSC) or ‘C.Spec.’
was established as far back as the late 1960s.

Using WBS was limited in the 1970s and 80s because of its
close association with the relatively complex C.Spec. total
system.

In the 1990s WBS was gaining more widespread adoption in
private industry.

Many Project management software packages today are
incorporating WBS as integral to their use.
Definition

A work breakdown structure, according to the Project
Management Institute, is a product-oriented “family tree” or
hierarchal listing that allows the total scope of the project
to be organized and defined.

WBS starts with a single box at the top that represents the
whole project which is then partitioned into its components
with lower level boxes.
WBS Structure
LEVEL 1
LEVEL 2
LEVEL 3
LEVEL 4
The Project
Example
Developing WBS
1.
Identify the major project elements (usually the project
deliverables plus project management functions).
2.
Decide if adequate cost and duration estimates can be
developed for each element at this level. If so, go to step 4.
3.
Subdivide each element into smaller components that can be
identified in terms of tangible, verifiable results. These
components should reflect how the project will be
accomplished.
4.
Verify the decomposition by determining if all lower-level items
are necessary and sufficient for completion of the item
decomposed.

Each item should be clearly and completely definable by a brief
scope statement.
WBS Role

Partitions the major project deliverables into smaller
components to improve the accuracy of cost estimates.

Provides a mechanism for collecting and organizing actual
costs.

Provides a mechanism for time, cost, and performance
tracking.

Allows establishing responsibility assignments for each
element.
WBS Role (Cont.)
The WBS allows:
 Program description as the summation of sub divided
elements.

Linking Objectives to company resources in a logical
manner.

Schedules and status-reporting procedures.

Network construction and control planning.
Applying WBS

The work sequence affects the WBS and the WBS affects the work
sequence.

Size of the WBS reflects the time the project manager needs to
spend to coordinate the elements. As the size increases,
communication requirements grow.

Therefore a project should not be decomposed into any larger set
of elements than is necessary to deliver a quality project in a
timely manner.

Each item in the WBS is generally assigned a unique identification
code to facilitate this process.
Project Coding System

Project coding system is used to structure the project,
identify the cost accounts, WBS elements, and establish
their relationships.

Coding simply involves using a multi-digit number, or
assembly of numbers and letters, each of which, or a
combination of which, has a meaning or significance.

Each code number uniquely identifies a cost account, WBS
element, and their parent-child relationship in the WBS.
Example
Program: New Plant construction and
Start-up
01-00-00
Project1: Analytical Study
Task1: Marketing/Production Study
Task 2:Cost Effectiveness Analysis
01-01-00
01-01-01
01-01-02
Project 2: Design and layout
Task 1: Production Processing Sketches
Task 2: production Processing Blueprints
01-02-00
01-02-01
01-02-02
Project 3: Installation
Task 1: Fabrication
Task 2: Set Up
Task 3: Testing and Run
01-03-00
01-03-01
01-03-02
01-03-03
Project 4: Program Support
Task 1: Management
Task 2: Purchasing Raw Materials
01-04-00
01-04-01
01-04-02
WBS Rules

Elements should reflect the number of subcontracts.

Both the WBS and work description should be easy to
understand.

All schedules should follow the WBS.

No attempt should be made to subdivide work arbitrarily to
the lowest possible level. The lowest level of work should
not end up having a ridiculous cost in comparison to other
efforts.
WBS Rules (Cont.)

The WBS should remain flexible to accommodate scope-ofeffort changes.

Elements should identify discrete and tangible milestones.

Activity element levels should reflect a trust in certain
groups to perform their responsibilities.

Most lowest-control-level elements should range from 0.5%
to 2.5% of the total project budget.
Conclusion

The WBS diagram can be developed by hand. For large
projects, when there are dozens of activities that need to be
identified, developing the WBS is done using a software.

WBS is a very valuable tool for managers because it helps
them plan and control their projects.

When developing a WBS, a set of rules should be followed
to guarantee reaping its maximum benefits

For instance, managers should avoid planning unnecessary
activities so they do not waste money and time on them.
Thank You
Ready for Your Questions