The 100% rule

What is the 100% rule?


The 100% rule (Haugan, 2001, p 17), is a core characteristic of the WBS.This rule states that the WBS includes 100% of the work defined by the project scope and captures ALL deliverables – internal, external and interim – in terms of work to be completed, including project management. The 100% rule is one of the most important principles guiding the development, decomposition and evaluation of the WBS.The rule applies at all levels within the heirarchy: the sum of the work at the “child” level must equal 100% of the work represented by the “parent” and the WBS should not include any work that falls outside the actual scope of the project, that is, it cannot include more than 100% of the work
It is important to remember that 100% rule also applies at the activity level. The work represented by the activities in each work package must add upto 100% of the work necessary to complete the work package.


Where is it used?



It is used in the creation of WBS.


Why is it important?

  1. It ensures that the scope of the project is completely mapped.
  2. It helps to avoid gold plating.