Selection of ergonomic risk assessment method with pythagorean fuzzy sets: practice in emergency medical services

What is it about?

It is difficult to evaluate ergonomic risk factors in occupations with unpredictable tasks, random demands, and variable settings such as emergency medical services (EMS). This study deals with the problem of selecting an ergonomic risk-evaluation method with Pythagorean Fuzzy Sets (PFSs) based Pythagorean Fuzzy AHP (PF-AHP) and Pythagorean Fuzzy WASPAS (PF-WASPAS) methodology. The method selection criteria were obtained by consulting five different anonymous experts on the candidate criteria obtained from the literature review. The final four main criteria and ten sub-criteria were then decided. After the determination of the decision criteria, five experts were asked to evaluate the criteria and to express their opinions on criteria-alternative scoring by means of a questionnaire for method selection. A two-step method is suggested for the selection of the ergonomic risk-evaluation method. In the first step, PF-AHP is utilized in order to identify the weight of criteria used in the method selection. In the second step, the PF-WASPAS method is proposed in order to OWAS, RULA, and REBA methods. The accuracy and validity of the suggested hybrid model is tested with real data in İstanbul Ambulance Service stations. A sensitivity analysis is carried out to test the reliability of the model. Moreover a comparative analysis is carried out with AHP and Fuzzy AHP methods to identify criteria weights. Study results show that REBA is the most appropriate ergonomic risk-evaluation method in EMS.

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Photo by Renato Marques on Unsplash

Photo by Renato Marques on Unsplash

Why is it important?

The goal of this study is to identify the most appropriate ergonomic risk assessment method among the three observation methods used in the field to assess work-related musculoskeletal system loads of employees, based on the criteria identified specifically for emergency medical services. A two-step method was suggested in this study for the selection of the ergonomic risk-evaluation method. In the first step, the Pythagorean Fuzzy AHP (PF-AHP) is applied to determine the weight of the criteria. In the second step, the Pythagorean Fuzzy WASPAS (PF-WASPAS) method is employed in order to rank the ergonomic risk-evaluation method. The main contributions of this study are as follows: – To the best of the authors’ knowledge, this is the first study that presents a comprehensive, reliable and valuable framework to select an ergonomic risk assessment method to evaluate work-related musculoskeletal system loads of emergency medical services employees. – To the best of the authors’ knowledge, this is the first study that hybridizes the AHP and WASPAS methods based on PFs to select the most appropriate ergonomic risk assessment method for the study of work-related musculoskeletal system loads of employees for emergency medical services. – The proposed PF-AHP & PF-WASPAS method copes with uncertainty by enabling decision-makers to express their opinions more flexibly. – A sensitivity analysis is performed to reveal the robustness of the suggested method to the variation. And also to verify the validity of the introduced method, we compared the PF-AHP& PF-WASPAS approach with the proposed F-AHP& PF-WASPAS, and AHP&PF-WASPAS approach, respectively.

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