ITO,
I have yet to figure out how to get one man in a truck to generate $1000+ before materials/day with T&M. (Not counting emergencies or overtime)
The tech earns roughly 25% (total cost to me with burden is about 35%). So he gives me 8 hrs, actually works for 4+/- and earns $1000-1500/week in the pocket. Plus benes, truck, etc.
When we were a union shop, we operated just like you. But we did very little service work. Only for a few customers. They would pay us 4 hr mins (because we installed the equipment and it was cheaper to pay us than to try to get someone new to understand the systems)
But most of our work on installs was T&M as well. warehouses at T&M, it was a different time. So we made money when the guys put things in wrong and we made money when they redid them.
The big difference was we got paid for every hour that the man was paid. With service work, we have too much downtime. With residential service work, we have too many people who don't understand why they have to pay us for 2 hrs when we were only there for "20 minutes". So flat rate alleviates those issues on the resi side. Plus, I end up with a higher hourly rate than I would ever get on T&M...