By now, most of you have been exposed to enough quality and continuous improvement training that you're familiar with the tools of the trade -- the Five Whys, fishbone charts, SPC charts, and so on. They're all ways of taking a logical, thorough, disciplined approach to isolating a problem.
In many of the same plants where these techniques are practiced faithfully, though, I've seen people struggling mightily to get their process heating equipment operating reliably and consistently. It's as if all this quality methodology somehow stops at the oven door and waits outside during the heating cycle. Yet product quality and productivity always will be vulnerable if that oven isn't doing its job properly.
The ability to troubleshoot equipment or systems is one of the most important skills you can have today. Some people are naturals at it -- their thought processes are logical, and they can cut through the clutter that obscures the problem's root cause. For the rest of us, however, it's an effort. This column begins a short series on troubleshooting your ovens and their heating systems.
I'll begin with a little philosophy -- the principles that underlie your efforts. Here are a few that seem to have held up well over the years:
Divide and Conquer. Break the problem up into smaller and smaller pieces until you can isolate the cause. To do this effectively, you need to have a good understanding of the system's operating sequence.
Ask Questions. Asking "Why? When? Where? How often? How long?" etc., will help you isolate the cause. Keep asking until you get the answer. This is just a variation on the Five Whys, but these questions fit the operation of heating systems a little better than "Why? Why? Why?"
Remember that very often, the person complaining about the problem may also be responsible for it, so they will be less than honest in replying to your questions. Keep asking the questions from slightly different angles until the truth is exposed. The point is not to catch someone with an "Aha!" but to fix the problem.
Be Deliberate. When you're trying to figure out why equipment isn't working properly, don't make that leap from Step 1 to Step 10 in the logic process. Instead, work back from the present problem to the origin in a step-by-step fashion. Make the following assumptions in this order, and if the assumption can't be proven, move on to the next one.
A. If the equipment worked in the past, but doesn't now, something has changed:
-- Something is out of adjustment or broken.
-- The process has changed somehow, and the equipment no longer satisfies its needs, even though it might be working right. It's not unknown for someone to spend a day or two trying to adjust a heating system in response to complaints about slow recovery or insufficient temperature, only to learn that the production rate had been jacked up beyond the system's capability.
B. If the equipment has never worked right:
-- At first, assume that it's the right equipment for the job, but somehow it has never been set up or used correctly. Maybe no one was ever taught how. This is especially true when the equipment is new. If the problem has persisted for at least 6 months, start looking for another reason.
-- If the equipment still won't work after everyone's best efforts, it may have had some defect from Day One. Try to find out if such a defect exists, even if it means calling in an expert to study it. The best place to start is the equipment manufacturer. Who knows it better?
-- If no one can find anything wrong with the equipment, chances are it was the wrong selection for the job -- wrong size, wrong model or whatever. Most likely, the only solution is modifying the equipment or replacing it with something else better suited to your needs.
Focus on the Current Job. Just because some solution worked for you in the past, don't assume it will again. Reliving past glories too often can tarnish them.
Don't Make It Harder Than It Has to Be. Everyone's under the pressure of time, so when you have the choice of several fixes to try out, do the easy ones first.
- Be the Tortoise, Not the Hare. And finally, before you act, think. We tend be impressed by those people who jump right into action without hesitating a moment, but in my experience, the people who take a few minutes to make some observations and ponder the problem usually finish first.