requirement

A condition or capability needed by a user to solve a problem or achieve an objective that must be met or possessed by a system or system component to satisfy a contract, Standard, specification, or other formally imposed document. [After IEEE 610]

Terms of Software Testing (ISTQB)

every kind of supplies and service required for organization, equipment and operation and for every kind of activities of a trop but not ensured/supplied. Requirements are stated in Table of Organisation and Equipment or determined in accordance with Concept Based Requirements System.

Defense Procurement Terms