Hi I am sathya -- 2.7 year old testing professional. Let me answer to ur question.
First study the Requirements Specification well and understand the process/program flow of the application or the product.
The testcases what u r going to write depends on the kinds of testing that u do. If it is GUI kind of testing u should have the design document and sample application or some prototype that implements the flow of the application/product.
If u do Funtional Testing, u can infer information from SRS & get information from the development team for the program flow and the logic.
Follow the quality process and frame testcases accordingly.
When u write testcases ensure that u will cover the scenario to the possible extent.
U should be good in framing the "Expected result" of a particular program behaviour.
So that on executing your testcases u will come to know where it fails. Log the defects after you come across bugs in the product/application and send it to development team for closure.
Thanks & Regards,
Testing -- A critical discipline of finding
fault with the system.
I am just adding some information in the previous one.
Testing is process to find the bugs, which are not find yet. And Test case are set of step by which we try to find all those bugs.
Best test case are those which are as per system requirement and try to find the bugs. Test case may be for different type of testing like functionality, performance…etc but the procedure to write test case is generic….
1) Define your testing pre-requisites
2) Define the functionality which has to be test.
3) Define the test inputs (test steps…etc)
4) Define the accepted output. (Test results)