Detailed Design Assurance

At the detailed design (synthesis) phase, assurance engineers are not deeply involved with verifying the design. The majority of assurance activities are process assurance oriented, such as:

• Verify that the design process, as defined in the project plans, was followed.
• Verify that the tools specified in the previous phase are the ones that are being used.
• Verify that the configuration management system is being used as defined in the project plans. Ensure that any scripts used in synthesize are identified and controlled.

Use the Tailoring chart to determine which activities or analyses are required for a particular criticality classification. Activities that are not required may still be performed, if desired. Assurance activities for complex electronics detailed design include:

• Engineering Design Review
• Process Verification
• Update Risk analysis

Every method listed above does not have to be applied to every project. The table below uses the Complex Electronics Classification to map the activities, and depth of each activity, against the classification. This table allows for easy tailoring of the assurance activities to the device complexity and criticality.

Engineering Design Review

The Engineering Design Review (EDR) is an in-depth review of the design by engineers and assurance personnel within and external to the project. The goal is to find any problems with the design prior to it being programmed into the production (flight) boards. The Engineering Design Review is discussed in the Develop Detailed Design page.

Process Verification

Process verification is an activity performed at each life cycle phase. The plans that were generated at the beginning of the project should be followed as the complex electronics is developed. Assuring that the processes are followed is one way to help the project stay on track. Processes are not written in stone, but can be changed to reflect project reality. One result of process verification is to advise the project that updating the processes is a necessary activity.

For the detailed design phase, the assurance engineer will:

• Verify that the entrance criteria was met before the project moved into this phase. If not, document the increased risk due to non-approved architectural design or other issues. Provide risk mitigation suggestions to the project.
• Verify that the exit criteria is met before the project moves to the Implementation phase. If not, document the increased risk due to non-approved design or other issues. Provide risk mitigation suggestions to the project.
• Check that the Design Description and other documentation is complete and documented in a level of detail sufficient to proceed with the Implementation.
• Check that the planned measures, tools, methods and procedures have been applied.
• Ensure that the complex electronics detailed design is under configuration control. At the end of the phase, ensure that the detailed design is approved and baselined.
• Verify that all planned activities for complex electronics were performed.

Additional assurance activities require someone with expertise in complex electronics. They can be performed by the quality assurance engineer or by an engineer independent of the project.

• Review the constraints specified by the design engineer as input to the synthesis process for reasonableness.
• Assess the simulations that were performed after design synthesis is completed. Did the addition of timing information affect the outcomes of the simulations? Did the simulations look at worst-case timing, including incoming signals?
• Ensure that timing simulations or static timing analyses were performed.
• Verify that the simulations performed included out-of-range inputs, inputs that arrived in an incorrect order, and other “real world” problems that can be anticipated.

Update Analyses

Analyses performed during the requirements phase should be updated at this time.

Risk Analysis

Evaluate previous risks to identify those that no longer apply or that have changed their priority based on changes in probability or impact. Identify any new risks relevant to this phase of development and determine which require mitigation plans. Check that preventive measures and/or contingency plans exist for all identified risk items and that the risk, with mitigations in place, is acceptable for moving to the Implementation phase.

Other Analyses

The other analyses, FMEA, FTA, Interface, and Traceability, do not require updates during this phase, unless there is a design change.