I once gave specific instructions for optimisation. At least I thought they were specific. What was "wanted" was step-by-step. Even to the level of, "run transaction SE24"... and somehow this is more efficient than me doing the change. It took 3 months to put in 18 recommendations that would have taken me a couple of hours. But I digress...
It turned out the offshore company's practice was to put newbies into the ABAP fixes sections and experienced people into the new projects/enhancements. Unfortunately, the newbies had never been taught anything about object orientation, so had no clue what I was saying to them. It also turned out that the "fix" section wasn't aware of the client coding standards.
This prompted a client trip to the offshore partner to address these issues. I wonder how many clients just put up with it?