Purpose of Software Testing

Software testing has three main purposes: verification, validation, and defect finding.

• The verification process confirms that the software meets its technical specifications. A “specification” is a description of a function in terms of a measurable output value given a specific input value under specific preconditions. A simple specification may be along the line of “a SQL query retrieving data for a single account against the multi-month account-summary table must return these eight fields ordered by month within 3 seconds of submission.”

• The validation process confirms that the software meets the business requirements. A simple example of a business requirement is “After choosing a branch office name, information about the branch’s customer account managers will appear in a new window. The window will present manager identification and summary information about each manager’s customer base: .” Other requirements provide details on how the data will be summarized, formatted and displayed.

• A defect is a variance between the expected and actual result. The defect’s ultimate source may be traced to a fault introduced in the specification, design, or development (coding) phases.