Vehicle Need and Transport Cycle

Why it matters

The vehicle need calculation is not an exercise in recreating the transport load. The load calculated and scope-verified in M8 is taken here as input. It must be known which quantity will be carried in which containers on which departure. The question asked in this lesson is whether there is a vehicle and driver arrangement that will do that work at the required frequency. While the total daily load looks light, a short departure interval may require more than one vehicle. Conversely, keeping many vehicles does not make a load that exceeds the limit on a single departure acceptable. Time, physical load and human resource are different constraints; each is verified separately.

After a vehicle departs, it cannot be used on another departure until it is ready again. The ratio of cycle time to departure interval gives the time-based lower bound of the number of vehicles needed in regular cycles of equal duration. The result is rounded up; a fractional vehicle cannot be used. This number does not automatically cover maintenance, breakdown, shared loading area and variable service conditions. If the cycle boundary is not complete, the formula can produce a wrong result even when it is applied correctly. If loading or empty container preparation has been left out, when the vehicle is really usable again is defined incompletely. First the scope of the work must be closed, then the number of vehicles calculated.

Driver capacity is independent of vehicle capacity. A second vehicle in parking does not move by itself while the same driver is on another route. The driver's duty time may not be only the time behind the wheel; loading, delivery verification and empty container work may also belong to the driver. Who does these tasks must be clear. If a driver will leave some tasks and drive another vehicle, the physical transition, priority and handover condition must be defined realistically. The same time interval cannot be written for two vehicles to the same person. Even if the total person-minutes look sufficient, if there is an overlap at certain departure moments the plan cannot be applied; the timeline is therefore a mandatory check.

The fleet decision is a decision on the service arrangement before it is a decision on the number of vehicles to buy. The same demand can be carried with a longer interval; in that case the load of a single departure and the line-side stock may increase. The route can be split; the total path and driver work may change. Preparation can be moved to a separate source; the load on the new source must be kept visible. None of the options is evaluated by the vehicle ratio alone. Safe loading, suitable vehicle use and pedestrian passage are conditions to be preserved. Treating keeping many vehicles as proof of efficiency and choosing few vehicles as automatic success is wrong. The arrangement that meets the required deliveries and has all resource limits shown is accepted; conditions that stay open are stated separately in the decision. It matters not only that resources really exist but that they are suitable for the task. A vehicle with a different height or a different container arrangement may not be usable at every delivery point. For this reason an alternative resource is not accepted as equivalent just because it is idle in number; it is verified together with the task conditions.

Formula