I have 10+ years experience in Performance Testing and server tunings. The Estimate includes following.
1. Performance Test Planning, Performance Script / scenario identification and load distribution
2. Scripting for identified performance transactions and execution on stand alone (single thread / user).
3. Scenario execution (3 to 4 cycles) and result analysis. i.e. Average response time reporting and identification / reporting of application components with High response time.
4. Combined effort with client for Web/Application/Database server monitoring and to be done through additional tools i.e. SQL Advisor / Oracle Enterprise Manager for Oracle.
Note: Test data for each individual script creation, execution and Scenario execution to be provided by client before execution as per plan. Delay in test data and other client inputs (Script / scenario identification and load distribution as per business need) is not included in 20 days delivery time line.