We start with salesman getting the job first,
Then it goes to the engineering dept the head engineer lays out the equipment controllers, valves, actuators and etc. for each application, then seperates the programming into supervisor and device level then appoints the people to write the programs and do graphics, control start-up techs dump the programs in on site. Check them against the prints (wiring and logic) and start them up,tweek and troubleshoot whichever comes first.
The start-up techs are able to correct errors in programming and graphics, and rarely does an engineer need to visit the job.