How do you carry out an effective Critical Design Review (CDR)?

A Critical Design Review (CDR) is an essential formal checkpoint in the product development process. Undertaking CDR’S ensure designs are fit for purpose, ready for production and checked before further financial investment is made.

An organised and robust CDR helps to identify mistakes and highlight risks/concerns as well as highlight where further design improvements could be made. A CDR ultimately saves time and shares responsibility across all stakeholders.

• Check the assembly sequence and perhaps animate this using exploded CAD views
• Check any proprietary CAD Models against supplier datasheets – it’s surprising how often we find incomplete or incorrect models
• Ensure that all your pre-check activities have been recorded and are ready to present in a formal CDR

Once you have covered the above points, the next stage is to request a formal in-house CDR. You should invite the design team, design manager, and all key stakeholders such as manufacturing representatives and the client. Use BS.7000:2 to help you identify who should be in the meeting for your business.

• Walk the team through the CAD files, showing each part, sub-assembly and the general assembly by using section tools and isolated views, so that the detail is clear
• Explain the general functionality
• Discuss the key performance parameters
• Explain the intended use, user steps and experience
• Explain how the design will be manufactured including process, projected volumes and manufacturing cost estimates
• Explain how the design will be assembled, perhaps by using 3D CAD exploded views or simple animations
• Explain any design logic, calculations and FEA that supports the design
• Openly review the risk log (include technical, safety, project & commercial risks) and if applicable, review any other risk assessment methods, such as FMEA or Fault Tree Analysis (FTA)
• Senior managers should ask challenging questions throughout the process, with a view to finding solutions where possible. If there are no or few questions, it’s likely that people haven’t understood or are not paying attention. You need to be challenged now so don’t be afraid to remind them of their responsibility – it’s too late once the device is in manufacture!
• If the design is of a complex nature, then the senior designers reviewing the project should take more time to study the CAD files meticulously, measuring and critiquing the fine details of the design
• The Project Manager should record all comments, findings, concerns and further actions in a standard review template, using CAD screen captures for clarity

Following the meeting, minutes should be complied and distributed to those involved.