Vehicle Availability
The share of a fleet, or of a class within it, that is ready for service at a given moment. The positive framing of downtime, and the one most useful to a department.
Availability answers the question a department is really asking: can I get a truck today. It is normally expressed as a percentage of a class rather than of the whole fleet, because a 95% available fleet with every plow down is not 95% available to anyone who needs a plow.
Class-level availability is what makes the number honest, and it is where seasonal public fleets get misread. Snow equipment sitting idle in July is not unavailable, and a report that cannot tell idle from out of service will say the wrong thing about it. Availability is worth measuring hardest on the assets that have a season, and worth measuring during that season.
The target is a policy decision rather than a technical one. It depends on how much spare capacity a fleet carries, which is a budget question, and on what service level the departments have actually been promised, which is often nowhere written down.
