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Why Requirements Changes Are So Expensive

publish date: 2026/06/06 22:20:9.326953 UTC

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Why does a change to requirements usually cost more than a change at the design or code level?

Because a change to requirements usually means the system design and implementation must also be changed, and the system must then be re-tested

Because requirements engineers charge higher hourly rates than developers

Because requirements are written in natural language which is harder to edit than code

Because requirements documents are longer than design documents

Correct Answer

Because a change to requirements usually means the system design and implementation must also be changed, and the system must then be re-tested

Explanation

A requirements change ripples forward: it usually means the system design must change, the implementation must change, and the system must be fully re-tested. Each of these phases costs time and money, making requirements changes far more expensive than design or code-level changes discovered earlier.

Reference

Software Engineering, Ian Sommerville, 9th edition

Quizzes you can take where this question appears

Requirements Validation