80/20 Principle (aka "Pareto Rule") is a popular distribution assessment method that can be used to estimate duration of activities and tasks. The method is applicable to simple and routine tasks that do not require decomposition into smaller pieces.
The following action plan briefly explains how to use 80/20 Principle in estimating task duration:
- Set baseline duration for simple tasks. Baseline duration is a time period required to perform a routine task physically. For example: "send an email" is a simple routine task that physically consumes the time required for typing, formatting and sending a letter by email.
- Consider experience and skills of the assignee. It means baseline duration needs to be scaled to the amount of novelty of the task for the assignee. A more experienced employee will do a typical task quicker than a less experienced one. A more difficult task requires a more skilled assignee.
- Use 80/20 Principle to adjust scaling of baseline duration. Considering Pareto Rule, baseline duration needs to be adjusted to the following statement: 80% of a task’s outputs will be produced in 20% of the task’s duration.