Want to improve the quality of your product or service?
The number one, most significant thing you can do to improve your product quality is to reduce variation and create a culture that values variation reduction.
variation reduction
Reducing variation is one of the basic principles behind the Toyota Production System and the root of why Japanese cars had better quality than American ones. Reducing variation (and using statistical methods to look for variation) was a principle Edwards Deming brought to Japan after WW2. Deming worked with Japanese companies to create a culture of quality through reductions in variation and the rest, shall we say, is history.
Reducing variation is a basic idea that has been around for decades and I am kind of amazed at how few people have heard about it much less internalized it in the USA. While it is part of the culture in Japanese manufacturers, it is still a pretty foreign idea everywhere else.
Toyota was already legendary for their quality cars. When they had all those recall problems this past year, what was their response? Reduce variation by cutting the number of designs and the number of design groups even more than they already had. They doubled down on variation reduction.
The benefits of reducing variation are not just for manufacturing.
Do you frequently lose your keys or glasses or the TV remote? That is probably because you set them down randomly, ie a lot of variation. If you get in the habit of always putting them in the same place, you eliminate the variation and you always know where they are.
Lets say you are at a software company that makes several products. Several of them need to do the same task. The most common (but wrong) choice is to have each product write the task themselves. The right answer is to abstract the tasks and write it once in a reusable library that all the products can share. If the products want to customize it, they do that themselves or they change their design and stick to the common solution. This method will make it easier to test for problems, fix problems that exist, and it will create a common experience for users that is easier to use and understand.
Keep it simple, reduce the variation, and your quality with go up. Your productivity will also increase as there are fewer fires to fight and people are not repeating the same work.
Microsoft and Apple
A good example of the impact of variation is in personal computers. As it happens, the two largest personal computer systems in the world took opposite approaches to variation.
Microsoft Windows is unarguably the most popular desktop operating system in the world. 9 of 10 personal computers run Windows. While Windows has been successful, the business model is based on increasing variation. Microsoft only writes the software OS; it relies on thousands of hardware partners to make the actual PC's that we all buy.
A PC is actually a complex system. The CPU, motherboard, memory, video card, hard drive, power supply... all these components are designed and manufactured by different companies. Yet other companies take these parts, assemble them, add Windows and sell it to consumers.
Even though the "PC" is something of an open standard and companies are using the same basic designs, there is a ton of variation in building them. Using a different capacitor or a different factory can be the difference between "it works" and "I keep getting a blue screen". On top of that, many of the companies have different designs altogether.
All of these products ultimately run the Windows operating system and consumers associate their experience with Microsoft. Microsoft is responsible for their quality and the quality of their experience. Microsoft has to test them.
Testing software involves a test matrix. Take all the combinations possible, put them in a matrix, test each case to make sure it works. Even if you only stick to the highest level and list the number of products from each consumer PC company, that matrix is gigantic. Frankly it is a miracle that the PC works at all given its high level of variation. Your average consumer has no idea how much effort goes into making Windows work on so many hardware products.
At the other extreme is Apple.
Apple makes everything itself. It writes the software OS and designs the hardware which it then contracts out to manufacturing. Apple products are all controlled by a single company from start to finish. There are no clones, no partners, just Apple. Right from the start, Apple has reduced the variation people experience with an Apple product.
Apple has further reduced variation to the handful of models that it makes and supports. To reduce variation over time, they make their OS very inexpensive and expect users to upgrade. This allows them to focus only on the current products and spend very little time fixing past mistakes.
Even Apple's design philosophy is based on cutting features, reducing options until you only have the most needed things for a good experience. Critics argue that Apple products are too limited but Apple argues that good design stems from making decisions and limiting variation. (Although they dont use the variation word.)
While Microsoft 's test matrix is incomprehensibly large, Apple's test matrix is manageable.
the consequences
And the results?
The overall Apple experience is consistently better. By focusing on reducing variation in the hardware and the software, Apple has built a reputation for quality at the consumer level. Apple products just work. Fans know that Apple products wont do everything but they are confident that what the products do do, they do well. Measures of brand loyalty, brand recognition, revenue growth and stock price indicate that Apple is doing something people like,.
Despite Herculean efforts, Microsoft has the opposite reputation for many people. Window's PC's are complicated and break easily. You have to update video drivers, or call friends, or hire the Geek Squad. So many people spend time on tech support phone calls, it is a common cultural experience and running joke.
I would argue these two experiences ultimately stem from two different approaches to the principle of variation. Apple cuts variation and delivers higher perceived quality. Microsoft tries to give everyone everything and falls short. In effect, Microsoft chose the biggest hill to climb and then grows that mountain over time with even more choices. Microsoft's model requires them to expend increasing effort just to deliver the base level of quality.
In recent years, even Microsoft has been making an effort to reduce variation because someone recognized how much it costs. Specifically they have been reducing the test matrix by cutting support for previous products (which also have to be in the test matrix). Windows Live Messenger used to support many different versions; now they just support the current version and the previous version. Microsoft has also stopped supporting Windows XP. Even though there are a lot of customers using XP on new hardware, Microsoft needs to reduce its variations and stick to the current version and the previous version, Windows 7 and Vista respectively. It is just a start but still a good sign for consumers.
a variation culture
So think about variation. Once you understand the significance of variation, you will start to see examples of it everywhere in your personal and professional life. Once you see it, you will see it everywhere.
Unfortunately that is just the start. The real impact comes from a culture of variation reduction, whether that is in your household or your company. Deming recognized 50 years ago that quality does not come from individuals, it comes from the culture individuals work in.
If you are the only one in your group that is trying to reduce variation, you will go insane. Your efforts will just feel like extra work to other people and the result will probably be even more tension and frustration.
Culture's that dont appreciate the principle of variation reduction are still trying to get better quality and the result is probably a culture of fire fighting. New problems never stop coming up, people work harder and harder to deal with the symptoms but they never make time for fixing the root cause, variation. The result is overwork, lower productivity, high stress, and frustration. Most cultures get addicted to fighting fires and fail to realize that the best approach to fighting fires is to prevent fires in the first place by reducing variation.
So once you see it in your own life, you need to try to get others to see it too and help create and spread a common understanding and culture about variation. "I am not asking you to do extra. If we do it this way, it is actually easier. There will be less problems and we will have more time to do other things." The principle of variation is a subtle but powerful mindset change that will have significant impact over time.
