Importance of WBS for project planning

Project planning

Project planning is the process of defining the objectives and scope of a project and deciding in advance the work, methods, sequence, time, cost and resources needed to complete it. The result is a plan that is used as the baseline for execution and control.

Work Breakdown Structure (WBS)

A WBS divides the whole project into smaller, manageable work packages in a hierarchy of levels.

House project
|-- 1 Site work
|     |-- 1.1 Clearing and layout
|     `-- 1.2 Excavation
|-- 2 Substructure
|     |-- 2.1 PCC and footing
|     `-- 2.2 Plinth beam and DPC
|-- 3 Superstructure
|     |-- 3.1 Columns and walls
|     `-- 3.2 Roof slab
`-- 4 Finishing
      |-- 4.1 Plastering
      |-- 4.2 Flooring, doors, windows
      `-- 4.3 Painting

Importance of WBS for project planning

1. Covers the complete scope. Every work item appears once, so nothing is forgotten and nothing is repeated.
2. Base for the activity list. Work packages are expanded into activities for the bar chart or network diagram.
3. Better estimates. Cost, duration and resources are easier to estimate for small packages than for the whole project.
4. Fixes responsibility. Each package is assigned to one person, contractor or section (responsibility matrix).
5. Basis for budget and cost control. Costs are collected package-wise and rolled up to higher levels.
6. Progress measurement. The percent complete of each package is combined into the overall progress.
7. Improves communication. The team and client share one understanding of the project.
8. Helps in contract packaging and procurement.