Requirements Coverage activities should be carried out before any kind of software testing takes place. The aim of requirements coverage activities is to demonstrate and share that the test team have an understanding of what needs to be tested in order to gain customer acceptance. For this, you need to know what are the requirements of the system under test. This information can be obtained from the customer, the business analyst, the system designer or the project manager and may be in the form of a combination of text and diagrams.
It is important to know the scope of your testing you want to make sure you include all the features your supposed to and just as important you don't want to test too much! You should also be clear on what types of testing you are required ro perform i.e. functional, performance etc.
So scope defined, you should have a list of requirements. Functional, Performance, Load and each of these requirements should be covered by at least one test case. At this stage to show this coverage you would for each requirement write the name of the test which would cover it. Eventually you should end up with a Requirements Coverage Report or a Requirements Traceability matrix.
by Herb Williams