In this work, we propose a fuzzy inference as a decision support system built in the MATLAB Fuzzy Logic Designer for evaluating manual material handling risk conditions. The input variables for the fuzzy decision were: (1) the total time duration of the manual material handling in one shift of 450 min, with 3 h considered the maximal exposition time; (2) 25 kg as a maximal mass reference which should never be exceeded; (3) the repetitiveness of the manual material handling task through the shift considering as the maximal frequency of four lifts per min. Results of 135 earlier direct ergonomic evaluations made using the method proposed by the ISO 11228-1 were used as validator results, and called “expected results”. The experimentation intended to simulate an ergonomic evaluation in different boundary conditions of work and verify if the fuzzy interface could correctly replicate the results of the ergonomic evaluations. As validation, the list with the 135 expected results was compared against the evaluation made by the fuzzy logic interface, called “Work_Conditions”. From the comparison, only three evaluations (0.02%) differed with respect to the expected results. Consequently, it is concluded that the fuzzy interface can be used as a tool for automating the determination of manual material handling ergonomic risk levels, with great precision.

An ergonomic intervention method based on QOC Matrix the workers’ voice was implemented in a study case. The diagnosis and analysis developed are used in improvement proposals for workstation redesign. The workers’ voice resulting from reports of the employee’ complaints and symptomatology was the base for a standardized method that comprises: (a) QOC questionnaire application, (b) risk factor categorization, (c) determination of unsafe and unhealthy ergonomic metrics, (d) figuring out the task content impact in the workers’ body, and (e) work system diagnosis. Since workers’ voice, the risk identification made included: (1) the task content linked to work method: repetitiveness associated with the sensor activation using the fingers and the repetitive movements include twist and the stretch of wrist, (2) workplace design regarding container height and injuries caused in wrists and elbows due to hits, (3) task developed regarding risk time exposition and workers position, and (4) workplace design regards to housing collector distance from filling area linked to workers position adopted for reach bags. Improvements included redesign of the workstation with a system of 90° exit discharge curve, one elevation system, and a photoelectric sensor in filling nozzle for automatic filling. As an improvement result, the activity called bags provision was eliminated from the task.

The purpose of this study was to propose an interactive computer system that utilises the MATLAB Fuzzy Logic Designer to measure the level of implementation of SDG 8, which focuses on sustainable decent work (SDW) and economic growth. This study used policies and laws as parameters to determine the presence or absence of SDW. The fuzzy method was implemented in car windshield manufacturing in the auto parts industry as a case study to define and quantify work conditions and to determine the level of sustainable decent work (SDWL). The study described environmental conditions, such as noise, lighting, and heat stress; ergonomic factors, such as exposure time, the mass of the object manipulated, and lifting frequency; and organisation at work, such as workplace violence, salary, and workday, as linguistic variables. The level of the presence or absence of SDW was defined as their membership functions. The resulting vectors determined the absence of SDW with a score of 1.5 in two linguistic variables: environmental conditions and ergonomic factors. Some features of SDW in the linguistic variable organisation at work had an SDW score of 5. The SDWL vector determined a final score of 1.24, indicating the absence of decent work in production areas. This study found that the workers suffer a lack of long and healthy lives and a bad standard of living without economic growth due to work-related musculoskeletal disorders and work illnesses, increasing their out-of-pocket spending and catastrophic health expenses. As a CSR approach, assessing SDWLs helped managers improve policies and work conditions.

The “QOC Matrix - the worker's voice” is a decision making tool for ergonomics issues developed by the Autonomous University of the State of Morelos in México. In this paper we show the second phase of the development, introducing new organization of the questionnaire elements that allows to define the ergonomic opportunity areas like workplace design and layout, task content, materials handling, work environment and psychosocial aspects, considered by the worker as an ergonomic risk. The new criteria include standards from three different countries; Mexico, Spain and United States of America.

Objective: A hierarchical cluster analysis for the cardboard manufacturing industry was developed with the aim of identifying similarities between workstations in terms of musculoskeletal stress factors (MSFs) and their impact on workers’ bodies. Methods: The hierarchical clustering analysis was conducted using data from 44 workstations, which included 6 body part divisions and 51 stress factors as variables with 36 answer options. Firstly, the content of the dataset was defined. Secondly, the data were agglomerated and classified into 3 clusters using Ward’s method based on the presence or absence of stress factors. Finally, the multivariable matrix was reduced to 2 factors: the x-axis representing the risk level of the workstation, and the y-axis representing the impact on the workers’ health. Results: The study found that workers’ knees were the most affected body parts, with 47 cases. The resulting work-related musculoskeletal disorders included tendinitis, arthralgia, chondromalacia, and gonarthrosis. The MSF with the most significant impact on the body’s health was fatiguing work that involves repeated jumps, prolonged squatting, or kneeling, present in cluster 1 and cluster 3. Moreover, two of the most common MSFs associated with repeated work positions were identified: a mild forward flexion of the back (63 cases) in combination with one leg being used more often to support the body (56 cases). Conclusions: It was possible to identify the main work-related musculoskeletal disorders and the associated stress factors for the cardboard manufacturing industry by using hierarchical cluster classification and analysis, enabling the classification of risk levels and the impact on body health for each workstation.