Time is money, and finding out how much time and money it will take to test a product is one of the first steps when working with a QA team.
Test Estimation is the process of calculating the time it will take to complete a task. Estimating test efforts is one of the main and important tasks in test management.
During this process, the following moments are estimated:
- the required resources to perform any project tasks (this includes employees, equipment, etc.);
- time spent on the project;
- knowledge and experience of team members (a team with low testing skills will take longer to complete the project than one with more advanced ones);
- project budget.
Today, there are numerous methods of project estimation. In this article, we will describe the most common estimation methods, as well as their advantages and disadvantages.
1. Work Breakdown Structure
This is a basic technique for dividing a project into smaller parts, with necessary time constraints. Since small tasks are much easier to estimate, they are distributed among team members. Each person takes responsibility for the task and delivers the result within a certain period of time. The WBS is the most powerful and effective method among the test time estimation methods.
2. Three-Point Estimation
The idea behind this method is to find the best and worst working conditions for your team. It's a statistical method, but it also breaks down tasks into subtasks (similar to the WBS technique). Each subtask should be divided into three possible scenarios:
- You have a talented team and all the necessary resources, there are no problems, everything goes smoothly, and you can complete the task in, for example, 100 man-hours (hours of actual human work). This is the optimistic scenario (О).
- You have a good team, enough resources, and almost everything is going right, sometimes with some problems, and you will complete the task in 150 man-hours. This is the normal scenario (N).
- The team is inexperienced, most situations do not correspond to the expected scenarios, you will have to solve numerous problems, and the task will be completed in 200 man-hours. This is the pessimistic scenario (P).
This way, you have three values: O = 100, N = 150, P = 200.
Now you can calculate the average value for the test estimation (E) using the following formula: