Most of what goes wrong on site was already true when the van left the yard.
Why it matters
A technician who arrives without the right product has two bad options: improvise or come back. A technician who cannot get in loses the whole slot. A technician who has not seen the last visit’s notes repeats work that was already done. None of these are performance problems; they are preparation problems wearing a performance costume.
How you notice it slipping
Return visits cluster around particular account types rather than particular people. Technicians spend the first ten minutes of each job on the phone. Stock runs out at the end of the week, every week, which is a reordering rhythm that does not match the route rhythm.
What to do
Build the check into the day before, where it is cheap, rather than into the morning, where it is rushed. The shortlist is short: access confirmed, product on board, history seen, special requirements flagged. Four questions answered the night before will do more for finish times than any change to the route order.