Objective of test cases and pre-requisites to write the test cases

Following are the primary objectives of designing quality test cases.

• Find defects.
• Maximize bug count in the error prone areas of the product.
• Help stake holders to make ‘Go’/ ‘No-go’ decisions
• Minimize costs incurred due to defects found post production release.
• Verify correctness of the product i.e. meets the specifications.
• Control and assure quality of the product.
• Ensure usability of the product.
• Ensure security of the product from the end user perspective. 

Pre-requisites for test case design:

• Through and careful study of the requirement specifications
• Clear understanding of the design and implementation details
• Analysis and identification of all possible scenarios
• Identification of the test environment and test types
• Have detailed information about related and affected areas of the requirement
• Have clear understanding about the application behavior under failure conditions.
• Refer to similar type of test cases from previous projects and try to reuse whenever possible.