Estimation is the process of finding an estimate or approximation, which is a value that is usable for some purpose even if input data may be incomplete, uncertain, or unstable.

The Estimate is prediction or a rough idea to determine how much effort would take to complete a defined task. Here the effort is the time or cost. A rough idea how long a task would take to complete. An estimate is especially an approximate computation of the probable cost of a piece of work. An estimate is a forecast or prediction and approximate of what it would Cost.

The calculation of test estimation is based on:

• Past Data and Past experience
• Available documents and Knowledge
• Assumptions
• Calculated risks

The common question is that “Why do we estimate?”
The answer to this question is very simple, it is to avoid the exceeding time and overshooting budgets for testing activities we estimate the task.

Software Estimation Techniques

There are some Software Testing Estimation Techniques which can be used for estimating –

1. Delphi Technique
2.  Work Breakdown Structure (WBS)
3. Functional Point Method
4. Three Point Estimation