System Requirement (glossary)
(1a) A statement that transforms the stakeholder, user-oriented view of desired capabilities into a technical view, of a solution that meets the operational needs of the user. (ISO/IEC/IEEE, 2015, section 6.4.2)
(1b) The System Requirement Definition process creates a set of measurable system requirements that specify, from the supplier’s perspective, what characteristics, attributes, and functional and performance requirements the system is to possess, in order to satisfy stakeholder requirements. (ISO/IEC/IEEE, 2015, section 6.4.2)
Source
(1) ISO/IEC/IEEE. 2015. Systems and Software Engineering - System Life Cycle Processes. Geneva, Switzerland: International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC)/Institute of Electrical and Electronics Engineers (IEEE). ISO/IEC/IEEE 15288:2015 (E).
Discussion
Both definitions are modified from the introduction to the Requirements Analysis process, there is no formal definition of the term "system requirement" in the standard.
The term (engineered system) has been substituted for the word (product) in definition 1a to better align with the terminology used in the SEBoK.
For a full discussion of the role and importance of system requirements in systems engineering see the System Requirements article.