Food inspector scheduling with outcome and daily-schedule effects

Abstract

Food-safety inspection is regularly executed by the government for quality assessment. Evidence from recent research demonstrates that inspection accuracy and consistency are affected by inspection biases that result from an operational decision: inspector scheduling. More precisely, an inspector's stringency in an inspection is affected by the inspection results at the previous-inspected establishment (outcome effects) and when this inspection occurs within a workday (daily-schedule effects). To our best knowledge, the impact of these effects on scheduling decisions has not been studied in the scheduling literature. In this paper, we study a novel food inspector scheduling problem with these effects, where the inspector should scrutinise establishments with different locations. The problem is viewed as a single-machine scheduling problem with a complex objective function including (i) inspection accuracy, (ii) inspection consistency and (iii) workload of the inspector. To facilitate quantitative analyses of these effects, we model them by sequence-dependent functions and formulate a mixed integer linear programming model. To overcome the computational difficulty in large-scale problems, an efficient Tabu Search algorithm is developed. Experiment results on 135 randomly generated instances with up to 50 establishments and 10 workdays validate the efficiency of the solution method. Besides, managerial insights are drawn.

Keywords:

• Inspector scheduling
• inspection bias
• outcome effects
• daily-schedule effects
• single-machine scheduling

Disclosure statement

No potential conflict of interest was reported by the author(s).

Acknowledgments

We sincerely thank the editor, area editor and anonymous reviewers for their valuable suggestions!

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Notes

1 https://www.fsis.usda.gov/#

2 https://www.thebalancecareers.com/government-job-profile-food-inspector-1669685

3 https://www.food.gov.uk/research/cutting-edge-regulator/consistency-in-regulatory-work

4 https://www.foodsafety.com.au/blog/everything-about-food-safety-inspection

5 https://www.fsis.usda.gov/careers/job-opportunities/career-profiles/food-inspector

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (NSFC) [grant numbers 71771048, 72071144, and 71871159 ].

Notes on contributors

Ming Liu

Ming Liu, received the B.S. degree in management science and engineering and the Ph.D. degree in management science and engineering from Xi'an Jiaotong University, Xi'an, China, in 2005 and 2010. He is currently an Associate Professor at Tongji University, Shanghai, China. His research interests include port logistics optimisation and production scheduling.

Hao Tang

Hao Tang, received the B.S. degree in logistics management from Nankai University, Tianjin, China, in 2020. He is currently working toward the M.S. degree in the School of Economics & Management, Tongji University, Shanghai, China. His research interests include production scheduling and heuristic algorithms.

Feng Chu

Feng Chu, received the B.S. degree in electrical engineering from the Hefei University of Technology, Hefei, China, in 1986, the M.S. degree in metrology, automatic control and electrical engineering from the National Polytechnic Institute of Lorraine, Lorraine, France, in 1991, and the Ph.D. degree in automatic control, computer science and production management from the University of Metz, Metz, France, in 1995. She is currently a Full Professor of operations research with the University of Évry Val dEssonne, the University of Paris-Saclay, Évry, France and a Co-Leader of the Algorithmic, Operations Research, Bioinformatics and Statistical Learning Group.

Zhanguo Zhu

Zhanguo Zhu received the B.S. degree in environmental engineering and the Ph.D. degree in management science and engineering from Xi'an Jiaotong University, Xi'an, China, in 2005 and 2011. He is currently a Professor at Nanjing Agricultural University, Nanjing, China. His research interests include Sustainable Agri-food System and System Optimisation.

Chengbin Chu

Chengbin Chu, received the B.S. degree in electrical engineering from the Hefei University of Technology, Hefei, China, in 1985, and the Ph.D. degree in computer science from the University of Metz, Metz, France, in 1990. He was with the National Research Institute in Computer Science and Automation, Metz, from 1987 to 1996. He was a Professor with the University of Technology of Troyes, Troyes, France, from 1996 to 2008, where he was the Founding Director of the Industrial Systems Optimization Laboratory. He is currently a Professor with ESIEE Paris, Universita Paris-Est, France.