Introduction to Work Breakdown Structure

What is Work Breakdown Structure?

A hierarchical representation of all tasks and sub-tasks in a project is called a Work Breakdown Structure. WBS is the heart of a project plan which provides the following information:-

• A listing of all the significant work.
• Clear task decomposition so that members can be assigned specific responsibilities.
• Method for time scheduling cost estimation and expenditure tracking.

The WBS development depends on many factors:-

• Project Management Style
• Organisational Culture
• Customer Preference
• Financial Constraints

WBS decomposes a given task recursively into smaller activities in this notation we represent all the major tasks that should be carried out to solve the given problem. Here root of the tree is labelled by the problem name followed by various tasks and activities which form the children of the root node.

Therefore to be able to complete a project in the least amount of time a manager breaks down larger tasks into smaller ones expecting to find more parallelism. however, it is appropriate to subdivide the tasks into units taking less than a week to execute.

Work Package: Lowest level of WBS where the actual implementation takes place is called a work package. These are the leaves of the hierarchical WBS tree.

Steps to Create Work Breakdown Structure

• Determine the problem statement or purpose of WBS.
• Partition the WBS into its major components.
• Partition each component into sub-components.
• This partitioning should step when we arrive at an easily implementable and manageable work package.

Representation of Work Breakdown Structure

We can represent a WBS in two ways:-

• Tree Structure Form or Hierarchical Form.

• Indented List Representation

0 Top Level Process or Product
   1.0 First Level Process or Product
   2.0 First Level Process or Product
       2.1 Second level Process or Product
       2.2 Second Level Process or Product
           2.2.1 Third Level Process or Product
           2.2.2 THird Level Process or Product
  3.0 First Level Process or Product
  4.0 First Level Process or Product
      4.1 Second Level Process or Product
      4.2 Second Level Process or Product
  .
  .
  .
  .
  N.0 First Level Process or Product 

Types of Work Breakdown Structure

Process WBS

This is a WBS form that partitions a large process into smaller sub-processes. Here, each process is further decomposed into tasks that can be assigned to individuals for accomplishments. It is used by project managers to manage their projects.

Product WBS

It is a WBS form that partitions a large entity into its components. Here each component and its sub-components are identified resulting in a clearer identification of the largest system.

Hybrid WBS

A WBS which includes both processes and product elements of a project into one WBS is called a hybrid WBS.

Approaches to Develop Work Breakdown Structure

Functional Decomposition Based Approach

This is the most common approach to WBS development and it is based on the functions of the software product.

Organizational Based Approach

A company has various organizational units like marketing, sales, operations etc and based on these units a WBS can be developed.

Work Breakdown Structure Example

Example 1 : Management Information System Application

• MIS Application Tree Structure Form or Hierarchical Form

• MIS Application Tree Structure Form or Hierarchical Form

0 MIS Application
  1.0 Requirenment Specification
  2.0 Design
      2.1 Design Database
      2.2 Design GUI
  3.0 Coding
      3.1 Code Database
      3.2 Code GUI
  4.0 Testing
  5.0 Documentation

Example 2: Air Traffic Control System

• AIC System Tree Structure Form or Hierarchical Form

• AIC System Tree Structure Form or Hierarchical Form

0 Air Traffic Control System
  1.0 Radar Segment
      1.1 Search Radar
      1.2 Digitiser
      1.3 Beacon Radar
  2.0 Terminal Segment or Tower Segment
      2.1 Communications
      2.2 Display
  3.0 Control Process Segment
      3.1 Radar Data Processing
      3.2 Flight Plan Processor
      3.3 Digital Processor
      3.4 System Utilities
  4.0 Communication Segment
      4.1 Ground to Air System
      4.2 Digital Network System
      4.3 Voice System
  5.0 Area Control Segment
      5.1 Communications
      5.2 Display