This is actually a very good topic that could be very different for everybody depending on your personal situation. I think in a perfect world, you should have all your trucks or service vehicles equipped and set up exactly the same way. You should even have a schematic diagram of that set up with all the tools and supplies listed. This way they should have whatever they need at all times and everyone knows exactly where it is and...where to put it away when they are done. Additionally, if a particular job requires a special tool that might not be standard on the service vehicle, then it should be noted on the work order for that job. A sign-off / completion sheet is a good idea too. This insures that the customer confirms they are satisfied, the job is correct, complete and the sign is working at time of completion, when the installation crew leaves.