Modelling water closet demand in shopping centres

Abstract

PurposeTo quantify water closet (WC) provisions in shopping malls in order to help building professionals to determine effective sanitary designs at certain service standards in terms of the user's probable waiting time.Design/methodology/approachThe proposed WC provision takes account of the probable waiting time corresponding to certain demand patterns of shopping malls. The probable waiting time for a WC and the failure rate of the closet in providing immediate service to the users at various WC provision levels described by a simple queuing process are evaluated by the Monte Carlo simulations. Model parameters such as the maximum waiting time expected by the users, the frequency distributions of the time between user arrivals and the service time at sanitary facilities were determined from a survey of a large shopping mall in Hong Kong.FindingsThe suitable provision of WCs was determined by the user's acceptable waiting time, and compared with those provision levels determined by the limiting failure rate of providing immediate service.Research limitations/implicationsThe model parameters are not exhaustive, with assumptions made for the queuing process of washroom users and have only been determined from a recent survey in Hong Kong, which perhaps will limit the model's usefulness elsewhere.Practical implicationsA useful source of reference in planning the sanitary facilities of shopping malls for various user demands. The methodology can be used in a modified form for most building types.Originality/valueThis paper proposes mathematical expressions for WC provision in shopping malls and presents a template to determine the required model parameters. The model offers practical help to professionals involved in planning, designing and managing the sanitary facilities of shopping malls.

Modelling sanitary demands for occupant loads in shopping centres of Hong Kong

“…The existing methodology does not refer to the arrival patterns from the design occupant load patterns in shopping centres. 13,14 In respect to the statutory requirements stating that an appliance is designated to serve a number of occupants, installations of WC appear to be satisfactory with the selection of the maximum allowable failure rate. However, due to this inadequacy of sanitary facilities, it has been reported that in some shopping centres there is a longer waiting time to obtain sanitary services.…”

“…However, due to this inadequacy of sanitary facilities, it has been reported that in some shopping centres there is a longer waiting time to obtain sanitary services. 14 Additional WCs have actually been installed in some shopping centres to reduce the probable amount of time for waiting at peak demands, thus enhancing the overall service of those centres. Additional provisions were determined by professional designers but without further feedback from users, the performance of each provision was still indefinable.…”