This process area describes three types of requirements: customer
requirements, product requirements, and product component
requirements. Taken together, these requirements address the needs of
relevant stakeholders, including those pertinent to various product
lifecycle phases (e.g., acceptance testing criteria) and product attributes
(e.g., safety, reliability, and maintainability). Requirements also address
constraints caused by the selection of design solutions (e.g., integration
of commercial off-the-shelf products).