The Definition of a Defect

When I talk to organisations about how to improve things something they all jump on is their quality, we must improve our quality. Great I'd say, so tell me what you mean by that, they would then typically run off a list of things that are found to be wrong with their products or service that either get to the customer or cause things to pile up at the door or in the process that stops it getting to the customer. That seems fair right? These are all defective parts, they can't be sold, or at least not at full price or not without rework, either way you are going to lose money on them.  

What is a Defect? 

The issue that many organisations have, however, is failing to understand stand that the pile of stuff at the door, not able to be shipped and needing reworked is not the defect, it's the outcome of a defect and it's important to understand that if you are going to fix things.

It's also important to remember that the word defect can be quite emotive, it can cause people to get defensive and invariably blame gets attached, which is crazy, because really what you are getting out is what your system is allowing you to produce. Your process is producing what it is designed to allow it to produce, if it does not produce what you expect there's a problem with the system, not the person!

So let's make sure that we understand that the definition is (1) an imperfection or abnormality that impairs quality, function, or utility it's a shortcoming or a flaw, which is defined as a defect in physical structure or form or an imperfection or weakness and especially one that detracts from the whole or hinders effectiveness.

If we simplify it down then, "a defect is an imperfection that detracts from the whole", it's a variation from what you expected to get , in lean we talk about variations from standard and when you think about it that's all a defect ever really is. You have a standard result that you expect to get from your process, you did not get that so there is a variation to that standard.

The Rework Isn't the Defect 

As we mentioned earlier everyone points towards the pile of parts that can't be shipped as the defects, it's not the defect. The defect is the variation from standard in the is process that allowed it to happen. That process could be anywhere (or multiple places):

• The sales process that miscoded the customer requirements
• The purchasing process that bought the wrong specification of materials
• The materials handling process that delivered the wrong specification of materials to the floor
• The engineering design that miscalculated the specifications
• The work instruction document that wasn't correct, or even worse wasn't there or was there but wasn't used
• The stamping process that used too much pressure
• The production planning process that produced more than it needed too or not enough
• The assembly process that put an untrained worker in the difficult position of trying to do a job they weren't trained for
• The training process that didn't capture and record or display easily that the person wasn't trained for the job

These are all defects, all opportunities for improvement, variations from standard, call them what you will but if you want to stop poor product getting to the back door or the customer, you need to find the real source of the issue, you need to find where the variation in the standards are occurring back up the line in the process and fix there, stem the flow of the errors in the system.

Take Time to Understand The Process 

When something isn't right, there is the immense pressure to get a fix, quickly! Let's get things back to normal, but if you take a short cut approach and just focus on fixing the surface stuff, the product that doesn't meet the standard and perhaps the initial next level cause of whatever process appears to be directly involved, then all you really do is plaster over the real problems. Taking the time in the short term to really work back up the chain to really understand the root cause and fix that defect, ensure that they have the correct standard and that everyone is trained to work to the standard and that there are checks in place to monitor that standard means that you really will fix the issue once. Once fixed you start to have a stable process, stable processes invariably run faster than unstable ones since you only produce good stuff. With your now stable process you can produce as needed, until the next variation to a standard pop up, which you'll also spend time fixing to yet again improve the process and take it to a new level of quality and stability and allow even better output, and so the virtuous cycle continues.

Summary 

The Defective parts at the customer or the back door aren't really the problem, they are the output. Understanding that and then genuinely working to find the root cause process that isn't running to standard is the only way to really fix the problem and increase your productivity. Defects don't just show up in physical products, they are in every day processes and these are the places to focus if you want to improve your organisational performance.