Creative Invoicing

Same story different shop. Question - I cannot keep consistent profits in materials or labor and I am not sure why?  The answer - CREATIVE INVOICING!  What is creative invoicing, that is my term for moving $$$ around to make an invoice balance.  Management systems are helping a lot with this issue because you cannot juggle the numbers if you invoice through the management system.  But if you have an independent invoicing system sometimes matching the invoice to the estimate can be challenging and that is where creative invoicing comes in.  You take a little from paint materials or labor to pay for that part the tech put on the car that you did not know about.  It happens, you need the "LT" to go after Trailblazer and it wasn't on the estimate.  You order it, it is not enough to supplement so what do you do?  I suggest establishing an internal parts charge line to expense that part rather than deducting it from another area.  Once you start borrowing from different areas it becomes easy and it makes all your profit reports worthless.  If it is a dead expense make it appear as a dead expense and it will show up in net, where it should be, but don't steal from other entities.