Impact of the Load-Area Bypass Feature on Passenger Service Quality

A lift stop is unnecessary if a lift stops to serve a call, but no passengers enter or exit the lift. There are many reasons for such a situation. For example, a passenger accidentally makes a call to the wrong floor, or a lift stops to pick up passengers, but no one enters the lift car since the waiting passengers consider the car full. In this paper the focus is only on the latter mentioned case. Traditionally, such unnecessary stops are reduced by using a load bypass feature. In this feature, a lift starts bypassing registered landing calls when the car is loaded over a configurable limit, called bypass load. When there are only passengers travelling, the load bypass feature works well in eliminating unnecessary stops. Nevertheless, when passengers transport light objects with them such as luggage or shopping carts, the floor area of a lift car may be fully occupied but the load is still below the bypass load limit and as a result, unnecessary stops may occur. If information about floor area usage of a lift car is available, i.e., what is the occupied percentage of the lift floor area by passengers and their belongings, then unnecessary stops will be better prevented. This paper studies how the number of unnecessary stops is dependent on different factors such as traffic intensity and pattern, and how much passenger service quality is improved in conventional control buildings when the floor occupancy information of lifts is used, in addition to load, in the bypass feature by analysing simulation results from a large set of hypothetical instances. The set is formed by varying traffic intensity, traffic pattern, number of objects transported and their sizes, lift group size, as well as the floor occupancy threshold and measurement error.