Troubleshooting is a form of problem solving, often applied to repair failed products or processes.
Troubleshooting can be considered an art, considered easy by many. For those who make it look like an art and don't consider it to be easy, often feel like an investigator when they finally find that the reason that outlet in the master bathroom closet is reading Hot/Neutral Reverse is doing so because the GFCI down stairs on the front porch is wired incorrectly.
The problem you need to correct may not be this difficult or it may not be as simple as replacing a bulb in that light fixture that is not working, it could be the limit switch on the auxiliary heat strip on a heat pump that has quit working. No matter what it is that you need to repair you should have a fundamental knowledge of whatever it is you are working on.
Fundamental knowledge does not mean replace every part in a circuit until it works. This kind of repair is not troubleshooting, it is wasting time, costing the company you work for money on parts, labor and customer satisfaction (that’s a parts changer). Replacing the parts without proper diagnosis will not correct the problem but will ruin the new parts installed, cost more money and empty your inventory real fast. So when you go to repair anything, if you do not know how to repair it or troubleshoot it call for help or your supervisor. Or use the forum on Maintenace911.com or email us and we will give you the help you need and we will also try to find you training in your area if you want us too. We will help in any way we can to give you the right tools for the job.
So when troubleshooting do it right, do it safely and always use good new parts.