Assessing sustainability of food supply chains by using a novel method integrating group multi-criteria decision-making and interval Type-2 fuzzy set

Abstract

A framework is required to assess the current sustainability status of food supply chains (FSCs) and identify the weak aspects. This paper proposes a novel method integrating group multi-criteria decision-making and interval Type-2 trapezoidal fuzzy (IT2TrF) set to develop a sustainability index for FSCs. A food company and five industry experts are selected to participate in a case study to demonstrate the application of this method. Fifteen criteria and 33 sub-criteria related to the FSC are identified based on the available literature and the opinions of the participating experts. The company’s performance in terms of sub-criteria is obtained using the Bonferroni mean operator to aggregate the judgment of a group of experts. The best–worst decision-making method is applied to determine an expert’s weights of criteria and sub-criteria. Due to the existence of qualitative criteria, sub-criteria, and incomplete information in experts’ judgment, an IT2TrF set-based approach is utilized to obtain the overall sustainability index. The Euclidean distance measure is applied to determine the sustainability status through the entire FSC based on the IT2TrF calculations, and the FSC sustainability index is obtained. The case study results indicated a “very sustainable” sustainability status. Also, using the ranking score method and threshold analysis, nine weak points are identified, including efficiency, agility, professional development, modes of transportation, time utilization, equal opportunities, health and prosperity. In addition, improvement measures are suggested for each weak point. Finally, comparative analyses with other cases are carried out to validate the results. The results confirm the efficiency of the proposed model and its ability to include more levels of uncertainty than the conventional fuzzy approaches.

Appendices

Appendix 1

This appendix presents a comprehensive questionnaire to gather the experts’ opinions regarding the performance of the food supply chain for the sub-criteria level.

This questionnaire aims to gather your opinions on the performance of the below sub-criteria related to your system. Please rate each sub-criterion using the following linguistic terms: Poor (P), Medium Poor (MP), Medium (M), Medium Good (MG), and Good (G).

Criteria	P MP M MG G	Biohazard related materials	□— □— □— □— □
Efficiency	□— □— □— □— □	Modes of transportation	□— □— □— □— □
Client satisfaction	□— □— □— □— □	Capacity utilization of vehicle	□— □— □— □— □
Supply duration	□— □— □— □— □	Utilization of time	□— □— □— □— □
Agility	□— □— □— □— □	Engine performance	□— □— □— □— □
Professional development	□— □— □— □— □	Traffic, pollutions, and incidents	□— □— □— □— □
Wellness measures	□— □— □— □— □	Discharging	□— □— □— □— □
Welfare-related measures	□— □— □— □— □	Time of travel	□— □— □— □— □
Diverseness & structure	□— □— □— □— □	Signposting	□— □— □— □— □
Import’s transportation decrease	□— □— □— □— □	Food health	□— □— □— □— □
Quality of packaging	□— □— □— □— □	Equal opportunities	□— □— □— □— □
Recycling performance	□— □— □— □— □	Health & prosperity	□— □— □— □— □
Reusability	□— □— □— □— □	Number of jobs created	□— □— □— □— □
Water utilization	□— □— □— □— □	Employment performance	□— □— □— □— □
Water pollution	□— □— □— □— □	Social responsibilities	□— □— □— □— □
Energy utilization	□— □— □— □— □	Economical link to the communities	□— □— □— □— □
Ecological diversity	□— □— □— □— □	Ethical trading plans	□— □— □— □— □

Appendix 2

This appendix presents the TrFS data for the linguistic weights and performance ratings used in this study’s presented cases. Table 21 represents the data provided for the bridge construction project case in which ${W}_{ijk}$ are the linguistic terms for the importance weights of criteria ${SS}_{ijk}$, where i, j, k are the sets of dimensions, criteria, and sub-criteria, respectively. ${P}_{ijk}$ are the performance ratings for criteria ${SS}_{ijk}$. Similarly, Table 22 provides the linguistic weights and the performance ratings for the freight transportation systems.

Table 21 The linguistic terms of weights and the performance rating TrFS for the bridge construction project

Table 22 The linguistic terms of weights and performance rating Z-information for the freight transportation systems