Hmm ok so lemme ask this. I often hear management at the other big company I work for talk about margin. What are they talking about. Like they'll say "there's only 9% margin" or they'll say they booked a job at very low margin.
It is my understanding that the margin is the same thing as net profit. Net profit is the money left over after the labor, material, equipment, and overhead are recovered.
Overhead can be a bit more involved than a lot of small ECs understand. You can recover your overhead from your materials, your labor, a combination of materials and labor (and equipment).
A company I worked for paid for us to be trained in the dual overhead recovery method. It was based on what your budgeted labor sales and material/equipment sales were going to be. The projected overhead was turned into a multiplier on the labor or material/equipment costs. Then a profit margin was added.
For those interested, the mark up on materials was lower than the mark up on labor (for overhead recovery). This was back in the 90's so I don't remember a lot of the details, but I do remember thinking if you got it wrong that you would be driven to jobs that had a different mix of labor and materials and it would be towards the jobs that you didn't recover your overhead.
When I conducted my own business, I pretty much collected all my overhead on my labor sales. Materials/equipment would be marked up with a profit only. I don't know if that is correct or not, but it worked for me.