How to manage changes in requirements and specifications

Product requirements and specifications differ in flexibility during development. Requirements remain adaptable as new insights, feedback, or constraints emerge. This flexibility allows teams to refine priorities before heavy execution.

Specifications are far less flexible once development starts. They're written to achieve goals or fulfill requirements, so when requirements change, specifications often must change too. However, frequent changes cause confusion and rework. If requirements change after development begins, verify whether active specifications actually need updating.

For example, a PRD aims to increase conversion through a simpler checkout. Specifications are written, and development starts. If you discover the product page also needs improvements, treat them as separate specifications since they can launch independently.

If feedback reveals users prefer multi-page checkout, you face harder choices: assume the risk and measure the new experience, stop development to rewrite specifications, or halt development entirely. Managing both documents means finding balance—adjusting requirements as vision evolves while keeping specifications stable enough for reliable delivery.