Stability is underrated because it is invisible when you have it. You only meet it by losing it.
Why it matters
A stable route compounds. The technician learns the properties, so visits get faster and better at the same time. The customer sees the same face, so trust builds and cancellations fall. Dispatch stops rebuilding the same work every month and spends that time on the exceptions that actually need a human.
An unstable route compounds in the other direction, and the cost shows up in three different places — service quality, retention, office hours — so it is rarely attributed to routing at all.
How you notice it slipping
The same customer gets a different weekday each visit. A technician’s route looks different every month. Nobody can predict where anyone will be next Tuesday without opening the schedule.
What to do
Measure how many recurring appointments changed day or technician in the last cycle, as a percentage. Then look at what caused each change. Most churn comes from a handful of repeating causes, and each one is fixable once it has a name.