Lanes are the difference between a schedule that is built and one that is maintained.
Why it matters
Scheduling account by account means every new customer is an isolated decision, made with whatever information is on screen. Placing accounts into lanes means the decision is made once, against a pattern that already works, and the route stays dense because the lane was dense to begin with.
Lanes also make coverage simple. When a technician is away, a lane can be handed over as one unit with a known shape, rather than as a scatter of unrelated appointments.
How you notice it slipping
New accounts are placed wherever there is an opening. The same street appears in three lanes. Nobody can describe the week in fewer than fifty lines, which is a sign that the structure has dissolved into individual appointments.
What to do
Name the lanes and keep them few enough to say out loud. Then make lane placement the default step when an account is sold, with a deliberate exception path for the cases that genuinely do not fit. The exceptions are fine; the absence of a default is what hurts.