Clause 9.5: SyRS content
The SyRS records the technical requirements of the chosen system and the usability of the human-system interaction.
What clause 9.5 asks
The SyRS records the technical requirements of the chosen system and the usability of the human-system interaction. Its content covers the system purpose, scope and overview, the system context, functions and user characteristics, functional, usability, performance, interface and other quality requirements, modes and states, physical characteristics and adaptability, environmental conditions, security and information management, policy and regulation, life cycle sustainment, packaging and transport, verification, and assumptions and dependencies. Process requirements belong in the contract or statement of work, and if they are included they have to be identified as process requirements.
Why it matters
The SyRS is the acquirer's technical view of what the system must do. The content list is broad because a system has to survive its environment, its supply chain and its disposal, not only its functional test. The separation of process requirements is important: a statement about how the supplier will work is not a property of the system.
No clause level change is public for this unit; the DIS keeps the title and scope, and the requirement text is not released.
What good looks like
Use the content list as the specification outline. Mark a section not applicable with a reason where it truly does not apply. Keep the verification section aligned with the verification matrix, and the assumptions section aligned with the risk register.
Evidence an assessor asks for
The assessor will check that a non functional area such as environmental or security requirements is not empty. An empty section with no not-applicable reason is a gap.
- SyRS The baselined specification, organized to the clause 9.5 content list
- Context and interfaces The system context, external interfaces and user characteristics
- Quality and environment Usability, performance, security, environmental, physical and sustainment requirements
- Verification and assumptions The verification approach and the assumptions and dependencies, linked to the risk register
Where it commonly fails
- The SyRS covers functions only, with environmental and security sections left blank
- Process requirements are mixed in without being identified
- Assumptions are recorded in the risk register but not in the specification
What to do before the revision
Fill the content list before writing prose. The empty sections tell you which requirements conversations have not happened yet.
Read across
Source for clause 9.5: ISO/IEC/IEEE 29148:2018, Clause 9.5, retrieved 19 October 2026. The revision note rests on ISO page 94091. The requirement, evidence and gaps are written from our record. Every source.