Socio-economic design of control charts for monitoring service processes: a case study of a restaurant system

ABSTRACT

The main purpose of this paper is to design a control chart for monitoring the service processes in congested immobile single-stage service systems where customer arrivals are time dependent. It is investigated how social and economic/statistical aspects of the control chart can be addressed. As customer satisfaction is a key success factor for a service system, our proposed design method incorporates cost minimization and service quality maximization as two conflicting objective functions to constitute a bi-objective optimization model. The service quality is measured by the waiting time required to obtain a service, and a constraint is considered to guarantee the statistical performance of the control chart. Simulation-based optimization is used to obtain Pareto-optimal designs. A case study of a local restaurant is presented where the daily customers’ data are used to estimate the required parameters. The results show that the proposed method is able to make a trade-off between the quality-control cost and the customer waiting time. They also indicate how the resulting design is sensitive to the misspecification of the input parameters.

KEYWORDS:

• Statistical process control
• Quality control charts
• Queuing models
• Simulation–optimization method
• Socio-economic design

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. The code can be used freely for non-commercial purposes provided that the source is properly cited.

Additional information

Notes on contributors

Mohsen Ebadi

Mohsen Ebadi is currently a PhD candidate at the Department of Industrial Engineering & Management Systems, Amirkabir University of Technology (Tehran Polytechnic). He received his B.S. and M.S. degrees in Industrial Engineering from Iran University of Science and Technology and Khajeh Nasir University of Technology, respectively. His research interests are in the areas of statistical process control, applied statistics, and data analytics.

Amir Ahmadi-Javid

Amir Ahmadi-Javid is an Associate Professor at the Department of Industrial Engineering & Management Systems, Amirkabir University of Technology (Tehran Polytechnic). His research lies in the fields of risk analysis and management, data analysis, service system design and planning, supply chain management, project management, and quantitative finance. He is especially interested in studying engineering and management applications by developing mathematical models based on optimization, game theory, stochastic analysis, and statistics.