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Why Design Information Appears in Requirements
publish date: 2026/06/06 10:19:24.888764 UTC
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Ideally, system requirements should describe only the external behavior of the system. However, in practice design information sometimes appears in requirements. Which of the following are valid reasons why? Select all that apply.
Correct Answer
(1) You may need to design an initial system architecture to structure the requirements specification, and requirements are organized according to the sub-systems in that architecture
(2) Systems must often interoperate with existing systems, which constrains the design and imposes requirements on the new system
(3) The use of a specific architecture to satisfy non-functional requirements (e.g., N-version programming for reliability) may be necessary
Explanation
Three valid reasons design information appears in requirements: (1) An initial architecture is needed to structure the specification; (2) Interoperability with existing systems constrains design; (3) Non-functional requirements (reliability via N-version programming, certified architectures for safety) may mandate a specific architectural approach.
Reference
Software Engineering, Ian Sommerville, 9th edition