The customer requirements may be expressed in the customer’s terms and may be nontechnical descriptions. The product requirements are the expression of these requirements in technical terms that can be used for design decisions. Product and product-component requirements address the satisfaction of customer, business, and project objectives and associated attributes, such as effectiveness and affordability.
Design constraints include specifications on product components that are derived from design decisions, rather than higher level requirements. Derived requirements also address the cost and performance of other life-cycle phases (e.g., production, operations, and disposal) to the extent compatible with business objectives.
The modification of requirements due to approved requirement changes is covered by the “maintain” function of this specific practice; whereas, the administration of requirement changes is covered by the Requirements Management process area.