Document: NUREG-0800
Document ID: 4f141c71-35ca-4353-9047-a13efe6d56b7
Document Type: srp
Title: Revision 6 - August 2016
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1601/ML16019A308.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
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e device, even if logically impossible in the application (to account for sensor errors, communication line noise, and similar concerns). Safety means that the detailed design introduces no new safety hazards into the safety system. Security means that unauthorized changes are prevented, detected, or mitigated as appropriate per RG 1.152. Timing means that the time delay between stimulus and response is deterministic. SRP BTP 7-21 provides additional guidance on real-time performance. B.3.3.3.2 Process Characteristics of SDS The SDS should exhibit each of the following software development process characteristics: completeness, consistency, correctness, style, traceability, and verifiability. Completeness means that the detailed design specifies the actions of each software unit for the entire domain of each input variable (for example, the complete span of instrument inputs or clock/calendar time). The design should be sufficiently complete to permit implementation to take place. Actions should be specified for all situations anticipated in the SRS. Equipment, human, hardware, and software interfaces should be correctly and fully specified. Equations, algorithms, and control logic should be correctly and fully specified. BTP 7.14-59 Revision 6 - August 2016 Consistency means that the detailed design is consistent with the architectural design, and that the detailed design elements are mutually consistent. Design elements should be consistent with documented descriptions and known properties of the operational environment within which the software will execute. Input and output specifications specified in the software design should be consistent with interface requirements imposed by the hardware or pre-developed software products. Timing specifications of each detailed design element should be consistent with the timing specifications of the architectural element of which it is a part. Models, algorithms, and numerical techniques specified in the software design