Imagine if your doctor took your temperature but had no idea that it was supposed to be 98.6 degrees F. You can bet some lawyer could find out through his team of technical experts that the reason you almost died was you were at 106 degrees.
Day after day, your technicians are leaving a legal document (a work order) with a customer that contains information that the technician may or may not understand, writing things like verified correct airflow, checked charge, and verified temperature drop across coil.