This International Standard - specifies the required processes that are to be implemented for the engineering of requirements for systems and software products (including services) throughout the life cycle, - gives guidelines for applying the requirements and requirements-related processes described in ISO/IEC 12207:2008 (IEEE Std 12207-2008) and ISO/IEC 15288:2008 (IEEE Std 15288-2008), - specifies the required information items that are to be produced through the implementation of the requirements processes, - specifies the required contents of the required information items, and - gives guidelines for the format of the required and related information items. This International Standard is applicable to - those who use or plan to use ISO/IEC 15288 and ISO/IEC 12207 on projects dealing with man-made systems, software-intensive systems, software and hardware products, and services related to those systems and products, regardless of project scope, product(s), methodology, size or complexity, - anyone performing requirements engineering activities to aid in ensuring that their application of the requirements engineering processes conforms to ISO/IEC 15288:2008 (IEEE Std 15288-2008) and/or ISO/IEC 12207:2008 (IEEE Std 12207-2008), - those who use or plan to use ISO/IEC/IEEE 15289:2011 on projects dealing with man-made systems, software-intensive systems, software and hardware products, and services related to those systems and products, regardless of project scope, product(s), methodology, size or complexity, and - anyone performing requirements engineering activities to aid in ensuring that the information items developed during the application of requirements engineering processes conform to ISO/IEC/IEEE 15289:2011.