What is a product design review and how can you get the best results every time
We’ll take you through the main questions we get asked about product design reviews and provide tips on how to get the most out of the process.
What is a product design review?
Review detail varies with each engineering discipline. Each review checks the quality and completeness of work done. Reviewers look to see that i’s have been dotted, t’s crossed and ensure the output is fit for purpose.
To put this in context, here at Ignys we regularly undertake a variety of design reviews. These include our own engineers work during product development and as a check for some of our customers own designs.
Why do a product design review?
Put simply, they reduce the costs and delays caused by mistakes.
The earlier you find a mistake or omission the quicker and cheaper it is to fix. Design reviews make projects deliver quicker, reduce risks and lower development costs.
What types of design reviews are there?
- Schematic symbol and pcb footprint review
- Schematic and Design review
- Printed Circuit Board review
- Manufacturing Pack review
- Software release review
- Design for manufacturing review (DFM)
- Design for testability review (DFT)
- New product introduction (NPI) reviews.
Reviews are sometimes completed in conjunction with manufacturing partners. Other industry areas have their own relevant reviews.
Who should do the review?
When you’ve been working on a design for days, weeks or possibly months it’s easy to miss things that are right in front of you. It’s essential for another engineer to complete the review. Certainly with the relevant range and level of skills. For instance this can be internal within the team, a member of a different department or an external consultancy partner.
Reviewing your own work is usually of limited benefit. You bring the same assumptions and knowledge and can gloss over elements that you have looked at numerous times. One of our favourite areas here are connectors. It is so easy to get connectors wrong. This can be the schematic symbol, footprint numbering, top or bottom side connections, rotation, location and more.
What is the gold standard for Design Reviews?
Design review best practice requires the following:
- Use a competent engineer who isn’t the designer.
- Identify items for unique traceability. Drawing numbers and revision or similar is often used here.
- Make design notes, calculations, simulations, specifications and assumptions for the designed item available. This allows the reviewer to check over and confirm key calculations. As well as understanding the thought behind the approach taken.
- A checklist should be used. Combined with the reviewing engineer experience and judgement this helps ensure reviews are consistent between team members. It also means that all key areas are checked.
- Consider each item individually to avoid bias from the designing engineer. Check that all specification requirements are being addressed and that their implementation is good.
- Document and categorise each finding. Not all comments are showstoppers, some may be nice to have and some very serious. You must be able to differentiate between them.
- Designers and reviewers meet to discuss the review findings with a constructive and collaborative mindset. The designer retains design authority and responsibility for the design and should be free, with justification, to discount the advice given.
- The updated design following changes from the review should have just the changes checked. This means that there should be no, non-review related changed introduced.
- Design reviews need to be embedded into the overall design process as a stage-gate requirement. Before proceeding into the next stage of development the review findings should be addressed, agreed and completed. Project flow has “In-review” as a stage. The work is not complete until the review is complete.
- The team strives to get items reviewed as early as possible and not let them pile up.
- Add additional findings that weren’t part of the checklist to the checklist for continuous improvement.
- Feedback issues identified after the review when prototypes are received, production begins or if quality issues are later found.
What are the extra benefits of design reviews?
They create the opportunity for knowledge and best-practise sharing.
Knowledge of the product itself is helpful for resource resilience. In other words the reviewer would be in a reasonable place to continue from the designer if necessary.
Best-practise can be passed both ways between the designer and reviewer and captured in a growing checklist for other engineers to use on future projects.
What to avoid in a design review
It’s vital to leave ego’s outside. Depending upon the company culture there is a danger that design reviews can become a point scoring, competitive exercise. Design reviews aren’t for proving who is the cleverest engineer, nor for the “I wouldn’t have done it like that” brigade.
These studies shouldn’t be an alternative to prototyping. A design review should make your prototype more likely to work first time. However it isn’t a substitute for making a few early prototypes. In the world of electronics the datasheet can be wrong (or at least misleading) and so the real proof is in a working unit or two.
We’ve found that reviews work best when they are short, time-bounded activities. Furthermore these should be proportional to the level of complexity and risk involved. The core purpose is to save time and costs. Reviews that last more than a few days or perhaps a week for highly complex products begin to detract from their benefit.
Avoid reviews being skimmed over or skipped. When teams are under pressure to meet deadlines there can be a strong temptation to quickly glance over a design, tick off the checklist without proper checking or not doing the review at all. This can result in silly mistakes being missed. Where manufacturing is involved skipping the review can set a project back by weeks and cost significant amounts of money to rectify.
When in the product development process should you do design reviews?
There is no single point when these should be undertaken. Perform each review as soon as the item is ready for analysis. There is no point evaluating something that is partially complete, and is likely to continue to change. It should be done at the point the designer believes the item to be fully complete and before the output from the current design stage is used either by another engineer or department or is sent for prototyping or manufacture.
What if my product is more of an idea at this stage but I still need the concept reviewing?
Product feasibility studies are a great way of assessing a product idea in terms of the technical feasibility and the commerciality of the product. These can still give many useful insights if you feel it’s too soon to get the most out of a full design review.
What to look for in an effective design review
Effective reviews are embraced by engineers and their management to help make the outcome productive. With some practise and the assembly of checklists reviews can be relatively quick to undertake.
Look to see evidence of reviews being completed, in full, before the release of an item. One easy way of checking for a culture of embedding design reviews is the checklists themselves. When was the last time they were updated?
What does a design review NOT do and what else you might need to do
They identify problems and concerns with an item. But the review itself doesn’t address these issues. Following a review a key step is to understand the reviewers concerns and put measures in place to address them where you agree it is necessary.
It is also unlikely to spot every single problem with a design. The intent is to catch significant issues that would prevent prototypes being useful and not to replace prototyping.
You will still need to test and validate the prototype whether it has been reviewed or not.
How can electronics design consultancies help with design reviews?
Using the expertise of a consultancy which is separate to your business has two main benefits. Firstly, we have additional expertise and domain experience. We are likely to spot areas that can affect reliability, tolerancing, performance, battery life or which could impact compliance.
Secondly by using a point of view which is outside of your business means the reviewer will not have unconscious bias. There will be extra transparency because they will be less worried about raising concerns that could affect the project. This also allows the product to be assessed outside the tunnel vision of the organisation. This way the product can be properly tested to see if it is commercially viable.
How does a Ignys design review work?
For reviews of our own designs, we have a strict set of checklists. These include ensuring items are drawn on the correct grid, PCBs have the right information on the right layer as well as connectors being the correct way around and ensuring circuit simulation is correct. The checklists extend over multiple pages and regularly have additional checks added to them.
Using schematic and design reviews, as an example, we make notes on both the schematic and the review checklist and scan these in as a record. There is little value in typing up a set of notes from review.
These notes are then run through between the reviewer and designer to explain and discuss the issues before an up-issued schematic is released for a delta review.
The “will it work” principle
For client reviews we focus more on the “will it work” principle. Each business has their own standards they operate to and so we apply just the technical parts and not the consistency and informational aspects. The findings are summarised in a report explaining the issues and grading them from “Best practise” to “Major”. Where major means that the board will not work through to Best Practise being a point of advice for future. The reviews are pragmatic and diplomatic to avoid causing upset within the companies engineering team.
The report is then presented and discussed with the client who can then choose to make their own updates. Alternatively they can ask us to make the changes required on a case-by-case basis.
Still got questions. Would you like to chat with us?
There are many companies who can help with design reviews and our Ignys team are just one option. If you’d like to ask us anything about reviews you can reach our team.
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The pros and cons of keeping your design and manufacturing partners separate
Another useful source if you are looking at design reviews
Design council – 10 useful things to look at in a design review