This paper presents a computerised system for scheduling frontline employees of a retail store. It determines the minimum staff level at the front office that is required to maintain an acceptable level of customer service, although customers arrive randomly at check-out stations and their order sizes fluctuate over time. A bi-objective mathematical model for scheduling employees is developed that balances labour costs with employees' schedule preferences while assuring service quality. Data collected from the Point of Sale (POS) system are integrated into a PC-based spreadsheet model. The practicality and usefulness of the proposed model were validated through its application to actual cashier scheduling problems encountered by a supermarket store.