Root cause analysis

– When you have a quality problem, you really want the permanent solution. You want to find the source of that problem so that, if possible, it can be eliminated. Many times, we address the symptoms of a problem, but that only provides a short-term fix. You want to deeply analyze the problem so that you can discover the root cause and remove it. This will give you a permanent solution. The best tool for a root cause analysis is the five why’s approach. This approach is pretty straightforward. Once you discover the problem, you continue to ask why until you find what is actually causing the problem. On average, you’ll find the root cause after asking why about five times. and unfortunately, many people stop there, apply a short-term fix and think the problem is solved. You must continue to ask why until you sort through all the symptoms and get to the root cause. Here’s an example. You notice that one key workstation in the factory breaks down soon after the day shift begins. It seems to happen three or four times a week and the machine is usually down about one hour for repairs. Why? According to the technician, a 15 minute daily maintenance is scheduled on the night shift, but it’s not being done. Well, this can easily be fixed by telling the night shift technician that this maintenance must be completed every night. But you’ve done this before. The problem goes away for a week or so and then it’s right back again. Because not meeting the maintenance schedule is only a symptom of the problem. It’s not the root cause. You must keep asking why. Well, why is the maintenance not being done? Because the night shift operator runs the machine right to the end of the shift. Why? Because his supervisor told him to do so. Why? Because the supervisor is evaluated by the number of products completed during his shift. In this example, the root cause is found by asking why four times. The problem is caused by the way performance is evaluated. To permanently remove the root cause of this problem, the supervisor should also be evaluated for meeting equipment maintenance schedules. Collect some data about how much production is lost each day when the machine breaks down and the factory manager will certainly approve this change. This example shows that the five why’s technique is a very simple tool that gets results quickly and it’s a foundation for effective, continuous improvement programs. Try it out at work. Look for a problem, especially one that keeps coming back. Ask why until you find a permanent solution. Ask why until you find a permanent solution.