Document: NUREG-0800
Document ID: c90016c6-e03f-4224-8ff3-87a6f7d3ca42
Document Type: srp
Title: Appendix 7-A
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0525/ML052500547.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
ith system safety considerations. The other characteristics discussed in this BTP are important contributors to the overall safety of the software-controlled safety system, but are primarily concerned with the internal operation of the software. The safety characteristic, however, is primarily concerned with the effect of the software on system hazards and the measures taken to control those hazards.  Security & The ability to prevent unauthorized, undesired, and unsafe intrusions. Security is a safety concern insofar as such intrusions can affect the safety-related functions of the software.  Timing & The ability of the software system to achieve its timing objectives within the hardware constraints imposed by the computing system being used. Software Development Process Characteristics  Completeness & Those attributes of the planning documents, implementation process documents and design outputs that provide full implementation of the functions required of the software. The functions which the software is required to perform are derived from the general functional requirements of the safety system, and the assignment of functional requirements to the software in the overall system design. Appendix 7-A Rev. 4 — June 1997 BTP HICB-14-5  Consistency & The degree of freedom from contradiction among the different documents and components of a software system. There are two aspects to consistency. Internal consistency denotes the consistency within the different parts of a component for example, a software design is internally consistent if no set of design elements are mutually contradictory. External consistency denotes the consistency between one component and another for example, software requirements and the resulting code are consistent with one another if there are no contradictions between the requirements and the code.  Correctness & The degree to which a design output is free from faults in its specification, design, and implementation. There is