The work breakdown structure (WBS)

A work breakdown structure (WBS) splits a project’s result into smaller and smaller parts until each part can be estimated, assigned and controlled. It is the foundation of the plan: the schedule, the budget, responsibilities and the Gantt chart are all built from it.

An example

Project “Launch a mobile app”:

1. Preparation
   1. Requirements
   2. Interface design
   3. Architecture
2. Development
   1. Back end
   2. Mobile app
   3. Payment integration
3. Verification
   1. Functional testing
   2. Load testing
   3. User pilot
4. Launch
   1. App store release
   2. Support training
   3. Marketing campaign

The top level is phases, below are work packages, below them tasks.

The 100% rule

The main WBS rule: the children of an element together describe exactly 100% of the parent’s work — no more, no less. If “Verification” lacks load testing, nobody will do it. If “Development” contains “Marketing campaign”, the work is counted twice or lost between phases.

Name results, not activities

WBS elements are best named as results: “Back end”, “User pilot” — not “develop” or “test”. A result can be accepted or rejected; an activity can go on forever.

How deep to go

A good lowest level is a work package that:

• can be estimated for duration and effort;
• can be given to one owner;
• takes from a few days to a couple of weeks;
• has a clear definition of done.

Too fine, and nobody maintains an 800-row plan. Too coarse, and “Development — 4 months” hides slippage until it is too late.

Numbering

Codes like 1, 1.1, 1.1.2 show where an element sits in the hierarchy. They make it easy to refer to work in discussions and to set dependencies: “2.3 starts after 2.1”.

Common mistakes

• A WBS as a to-do list by department. The structure should follow the result, not the org chart.
• “Invisible” work forgotten: approvals, procurement, training, documentation, data migration.
• No milestones. Add checkpoints: “requirements approved”, “pilot accepted”.
• Built once. A WBS is refined as the project becomes clearer.

What next

Once the WBS is ready, add durations and dependencies to get a schedule. How to do that is in “How to make a Gantt chart”.

Where to run it

In Etapero the work breakdown is edited like a spreadsheet: phases, work packages, tasks, milestones and goals, numbering, pasting rows, working from the keyboard. It can be loaded from Excel or CSV, and the Gantt chart is built from it automatically.