Welcome to my blog for all things related to business quality (processes, systems and ways of working), products and product quality, manufacturing and operations management.

This blog is a mixture of real-world experience, ideas, comments and observations that I hope you'll find interesting.



Prevention is better than cure

Many moons ago I was blogging about Corrective Actions and said that, whilst they were invaluable, taking Preventive Actions was even better, as it should stop the problems occurring in the first place, but is considerably more difficult!

I thought I should elaborate…

It is obviously more difficult to say whether it will rain tomorrow than to say if it is raining now. For Preventive Actions you are trying to predict future problems so that you can take action to prevent them occurring.

A number of preventive techniques are available for incorporating into your normal working practices on a regular planned basis – say monthly or quarterly – or at key stages of projects; make them part of the way you do business. The techniques include:


Failure Mode and Effects Analysis, or it’s process equivalent, is a well established technique for identifying what might go wrong with a product or a design or a process, what the probability is and what the consequence would be if it did go wrong. You can then look at the most damaging and take preventive action, perhaps by changing the design or process parameters.

Risk Analysis / Risk Reviews

A little like FMEA, risk management involves looking at where the risks are in an activity (such as an R&D project) and their likelihood of occurrence and impact. Once you have carefully evaluated what might go wrong you can devise mitigating actions to reduce their likelihood or impact. FMEA is really part of risk management, as are activities like Health and Safety and Fire Risk assessments.

SPC trend analysis

I blogged about Statistical Process Control last October and it is highly relevant to preventive techniques. At its heart lies the Process Chart, data that shows the variation in parameters and enables you to get processes under control. SPC helps to spot trends in data that aren’t causing current problems but, if left unchecked, could lead to future problems.

Customer satisfaction trend analysis

Just as SPC can tell you if your manufacturing processes are starting to drift out of control before they actually go out of spec, customer satisfaction monitoring can spot emerging discontent before it needs a knee-jerk reaction. Do you know what your customers really think about you? Are any of them becoming less content? Do you need to do something about it?


‘Highly Accelerated Life Testing’ works on the basis that high stresses applied for a short time will cause the same failures as low stresses over a long time. By applying increasing amounts of stress to a product you can reveal hidden shortcomings in the design which you can iteratively improve until they are no longer weaknesses; see my blog about HALT (June 2009).

Design Reviews

My old friend Nick Goy (sadly no longer with us) was a no-nonsense technology consultant who pooh-poohed management fads but was absolute master of the design review; he taught the rest of us how it should be done. Whenever he went to help new clients he did a formal design review; however clever the designers, however sophisticated the design, Nick would find the bugs. You can do the same, peer reviewing new designs before you commit a lot of time and money can be hugely beneficial in preventing problems further downstream if done properly.

Design For Manufacture

DFM aims to optimise a product’s manufacturability. Instead of designing the product first then working out a way to manufacture it, you start by optimising the production and test processes that are repeated hundreds or thousands of times then make the design (which you only do once) fit with them. It’s a great discipline to build in to your processes. Production Tolerancing (including techniques such as Monte-Carlo Analysis) is one of the best known but, too often, least well applied parts of DFM.


We had to get a Japanese buzz-phrase in somewhere! It’s a method for ‘mistake-proofing’ a process so that it can’t be implemented incorrectly through lack of skill or concentration or random error. For instance, you might ‘key’ connectors so that only the correct combinations fit together, or you might safety-interlock doors so they cut power when a door is opened, or provide assembly jigs so that components can only be fitted the right way round. Poka-Yoke is a ‘fail-safe’ technique.

…and I haven’t even touched on Product or Service Readiness Reviews, Preventive Maintenance, Competitor and Market Analysis, Lessons Learnt exercises, and a host of other valid preventive approaches.

Preventive Action is difficult to justify with a conventional cost/benefit analysis because how do you know what would have happened if you hadn’t used it? But if the alternative is simply to wait for problems to strike, then react when they do, you can see how taking Preventive Action can be attractive.

The quality gurus say that if you rely purely on corrective (Quality Control) techniques rather than preventive ones (Quality Assurance) you will suffer from problems that are expensive and damaging but can never be completely eliminated; a sort of ‘background radiation of quality problems’ that keep you in fire-fighting mode.

So, over the next few weeks, my plan is to expand on some of these techniques; I hope you will find the blogs interesting or, at least, a little thought-provoking.

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