We can define software quality assurance as process of checking that whether the product or service which is being developed is meeting the requirements of the customer or not.SQA plan must be prepared beforehand. Quality assurance covers all the aspects influencing the product or service quality, either individually or collectively. Quality assurance activity in system development involves the following activities
Verification: The process of evaluating software to determine whether the products of a given development phase satisfy the conditions imposed at the start of that phase. Verification is ensuring that the product has been built according to the requirements and design specifications. Verification ensures that “you built it right”
Validation: The process of evaluating software during or at the end of the development process to determine whether it satisfies specified requirements. In other words, validation ensures that the product actually meets the user’s needs, and that the specifications were correct in the first place, Validation ensures that “you built the right thing‖. Validation confirms that the product, as provided, will fulfill its intended use.
Testing:System testing represents the ultimate review of specification, design and coding. This review may be based on the feedbacks obtained from the users
Certification:Certification is the conformation of the correctness of the program. Hence certification is for providing the authenticity of the system design that is whether the system is according to what was aimed.