Design Specification

Design Specifications describe how a system performs the requirements outlined in the Functional Requirements. Depending on the system, this can include instructions on testing specific requirements, configuration settings, or review of functions or code. All requirements outlined in the functional specification should be addressed; linking requirements between the functional requirements and design specification is performed via the Traceability Matrix.

Design Specification Examples

Good requirements are objective and testable. Design Specifications may include:

• Specific inputs, including data types, to be entered into the system
• Calculations/code used to accomplish defined requirements
• Outputs generated from the system
• Explaining technical measures to ensure system security
• Identify how the system meets applicable regulatory requirements

System Requirements and verification of the installation process are usually tested in the Installation Qualification. Input, Processing, Output, and Security testing are usually tested in the Operational Qualification.

Due to the extremely technical nature of most design documents, there is currently some discussion in the industry about who needs to review the Design Specification. The Design Specification is reviewed and approved, at minimum, by the System Owner, System Developer, and Quality Assurance. Quality Assurance signs to ensure that the document complies with appropriate regulations and that all requirements were successfully addressed, but they do not necessarily need to review technical information.

Depending on the size and complexity of the program, the design specification may be combined with the functional requirements document.