There are two techniques used for test estimation
Metric Based approach
Relies upon data collected from previous or similar projects Ex if previous project was 1000 hrs long and testing was done for 300 hrs and bugs found were 50 so if our current project is 2000 hrs then testing should be around 600 hrs and number of defects around 1000. The data to be collected from previous projects should include
No o f test conditions
No of test cases written
No of test cases executed
Time taken to develop test cases
Time taken to run test cases
No of bugs found
Expert Based Approach Approach relies on the experience of experts of relevant task The experts re
BA
Developers
Analysts and Designers
Testers