Software Testing estimation process is one of the most difficult and critical activity. When say that one project will be completed in a particluar time at a particular cost, then it must happen. If it does not happen, it may result in peer's comments and senior management’s warnings to being fired depending on the reasons and seriousness of the failure.

Here are a few rules for effective software testing estimation:

- Estimation must be based on previous projects: All estimation should be based on previous projects.

- Estimation must be recorded: All decisions should be recorded. It is very important because if requirements change for any reason, the records would help the testing team to estimate again.

- Estimation shall be always based on the software requirements: All estimation should be based on what would be tested. The software requirements shall be read and understood by the testing team as well as development team. Without the testing participation, no serious estimation can be considered.

- Estimation must be verified. All estimation should be verified: Two spreadsheets can be created for recording the estimations. At the end, compare both the estimations. If the estimation has any deviation from the recorded ones, then a re-estimation should be made.

- Estimation must be supported by tools: Tools such as spreadsheet containing metrics calculates automatically the costs and duration for each testing phase. Also, a document containing sections such as: cost table, risks, and free notes should be created. Showing this document to customer can help the customer to decide which kind of test he needs.

- Estimation shall be based on expert judgment: The experinced resources can easily make estimate that how long it would take for testing.

Classifiy the requirements in the following categories:

Critical: The development team has little knowledge in how to implement it.

High: The development team has good knowledge in how to implement it but it is not an easy task.

Normal: The development team has good knowledge in how to implement.

Also See:

- Test Specification
- Test Planning
- Test Strategy - All Aspects
- Test Strategy