AS design assurance

Objectives

1. Create a design at tier n that ensures the safety requirements for tier n can be satisfied.
2. Justify the sufficiency of the design created at tier n with respect to the defined safety requirements.
3. Review the sufficiency of the design created at tier n with respect to the defined safety requirements.
4. Create the AS Design Assurance Argument.

Inputs to the stage

• [Q] : Safety requirements for tier n
• [X] : Design process for tier n
• [U] : AS design assurance argument pattern

Outputs of the stage

• [W] : tier n design
• [V] : AS development log
• [Y] : AS design justification
• [Z] : AS design review
• [AA] : AS design assurance argument

Description of the stage

This stage aims to provide assurance regarding the AS design. This stage is iterative as it considers the assurance of the design of the AS across multiple levels of design decomposition. This stage is also highly integrated with Stage 4 and Stage 6 in that it involves creating design proposals to meet the safety requirements (defined at Stage 4), doing analysis of that design proposal (Stage 6), then perhaps changing the design in response, updating the safety requirements, doing some more analysis, and so on across multiple tiers in order to create and assure a sufficient design.