Call-Giving Devices in Lift Traffic Design with a Destination Control System

In a Destination Control System (DCS), passengers use specific terminals in lift lobbies to give their calls. Often, a building security system is integrated with the lift control system: after having granted access at a security gate, passenger’s home floor is automatically sent to the lift control system as a passenger call. Immediately after registering the call, the lift control system allocates a lift to the call and announces it on a display attached to the terminal or the gate. So far, passenger interaction with these call-giving devices has been overlooked in lift traffic simulation, which typically assumes an infinite-capacity queue for the devices and does not model passenger walking from the devices to the lifts. Standard passenger service quality parameters such as waiting time are defined from when a passenger either registers a call on a landing or joins a queue. Thus, in the case of the DCS, service quality measures include queueing, interaction and walking time. This paper introduces a queue-theoretic model for call-giving devices based on average interaction time and verifies it by simulations. The model predicts queue saturation, which allows to define handling capacity of call-giving devices with 80% utilization factor. The effect of walking distance on passenger service quality is studied by gradually increasing the distance from zero up to a remote location corresponding to security gates. Usage data of call-giving devices from operational lift groups with the DCS is analysed and compared to the current practices of lift traffic design.