Cost-benefit analysis of a socio-technical intervention in a Brazilian footwear company

Influence of extended working hours and physical recovery on absenteeism in the footwear industry from a system dynamics model

Objectives. Work-related musculoskeletal disorders (WMSDs) are recurrent in the footwear industry, resulting in absenteeism. This study aimed to quantitatively analyze the influence of overtime work and physical recovery time on the occurrence of WMSD-related absenteeism using a system dynamics model. As ergonomic methods have limitations in quantitatively simulating the behavior of these relationships, the integration of computational modeling techniques has emerged as a methodological alternative to bridge this gap. Methods. An ergonomic work analysis (EWA) was developed in a production cell of a large company. A model of causal relationships (causal loop diagram) and a simulation model (flow and stock diagram) were then developed, where three scenarios for overtime and physical recovery time were analyzed. Results. Working an additional hour resulted in a 42% increase in physical overload, leading to 7.62 leave requests per year and 78.7 days of employee absenteeism. Increasing the physical recovery time by 15 min reduced the overload to 36.5%, resulting in 6.8 leave requests per year and 71.1 days of employee absenteeism. Conclusions. Properly managing excess workload and providing adequate physical recovery for professionals is necessary to mitigate the productivity impacts of absenteeism in the footwear industry.

Assessment of the musculoskeletal discomfort scale for upper limb among workers in inner Brazil

BACKGROUND

Work-related musculoskeletal disorders for upper limbs (UL-WMSDs) form a complex of occupational diseases common to many professions worldwide. UL-WMSDs are manifested in most cases by pain, resulting in musculoskeletal discomfort.

OBJECTIVE

This research aimed to evaluate the perception of musculoskeletal discomfort in workers from the interior of the Brazilian states of Alagoas and Bahia through the construction of a scale to assess musculoskeletal discomfort for upper limb.

METHODS

The discomfort assessment scale was constructed from self-reported pain symptoms by 420 workers from the inner regions of the Brazilian states of Alagoas and Bahia. The reliability and dimensionality of the collected data were analyzed by McDonald's Omega and exploratory factor analysis, respectively. Item Response Theory (IRT) was used to create parameters for the discomfort scale.

RESULTS

The musculoskeletal discomfort metric was constructed from the workers' response with six levels (varying from minimum discomfort to maximum discomfort). At the lowest level of the scale, workers indicated symptoms in the shoulders and wrists were rare. At the highest level of the scale, daily pain symptoms are reported in all regions of the upper limbs. The shoulders are the last region to develop extreme pain symptoms.

CONCLUSION

The metric was created to present satisfactory psychometric properties and capable measurement of the workers' level of musculoskeletal discomfort based on self-reported pain symptoms. Therefore, the metric can support measuring discomfort, contributing to decisions that improve a healthier occupational environment for the worker.

Construction of a Musculoskeletal Discomfort Scale for the Lower Limbs of Workers: An Analysis Using the Multigroup Item Response Theory

Musculoskeletal symptoms are a major occupational health problem in workers, and these can affect all professional occupations. Previous studies have proposed metrics capable of evaluating the musculoskeletal discomfort experienced by workers. However, no study has developed a metric that considers professional groups. Thus, this study aimed to develop a scale for musculoskeletal discomfort in the lower limbs to compare self-reported symptoms among education, health, and industry professionals. The sample included 159 teachers, 167 health professionals, and 401 industrial operators who relayed their symptoms using a diagram of the hips, thighs, knees, lower legs, and feet. Factor and multigroup item response theory analyses were used to construct a musculoskeletal discomfort scale consisting of seven levels and to assess and compare the identified symptoms. The results showed that the progressive evolution of discomfort differed for each profession, demonstrating that each context and work environment affects workers differently, which may explain the different patterns of symptom responses among professional groups.

Examining the relationship between human factors related quality risk factors and work related musculoskeletal disorder risk factors in manufacturing

This study addresses the relationship between human factors (HF) related quality deficits in manufacturing and work-related musculoskeletal disorder (WMSD) risk factors in production staff. A recent systematic review identified 60 HF-related quality risk factors (QRFs) in manufacturing related to product, process and workstation design stages. We investigate the extent to which these identified QRFs are also WMSD risk factors. Each QRF was examined for its relationship with WMSD using a 0 (no relationship) to 10 (strong relationship) scale rubric. The authors rated each QRF separately and then discussed and adjusted their ratings in a review session. Results showed that average median ratings were the highest for QRFs related to product design (8/10), intermediate for QRFs related to workstation design (7/10) and the lowest for QRFs related to process design (5/10). This emphasises the significant role of HF in system design in reducing both quality deficits and risk of developing WMSDs for manufacturing personnel. Practitioner summary: This study investigates whether human-related risk factors for product quality are also risk factors for work-related musculoskeletal disorders in manufacturing. Results showed a substantial relationship between quality risk factors and WMSD risk factors. This indicates the significant role of human factors in operations design in improving both system performance and human wellbeing.

Sickness absence from work in the footwear industry: A longitudinal study

BACKGROUND: Studies on illness in the footwear industry have prioritized specific work sectors and diseases. OBJECTIVES: To analyze the main factors related to sickness absence and the indicators of illness in terms of recurrence and workdays lost among workers at a footwear company, ranging from storage of raw material to distribution of the final product. METHODS: A total of 9072 cases of absence from work were investigated in shoe production units from 2014 to 2017. Univariate models estimated the risk of bodily dysfunction (physiological and psychological) and the severity of recurrence and work days lost. RESULTS: (1) Most production units and work sectors were related to one or more affected bodily functions; (2) Neuromusculoskeletal and movement-related functions and the work sectors of prefabrication; cutting, assembly and finishing; and quality inspection of the final product required a longer recovery time before return to work and had a greater recurrence of leave; and (3) Women seemed to be more affected than men in terms of the reappearance of symptoms. CONCLUSIONS: Illness differs according to occupational sectors. The production sectors present more serious situations due to physical overload, intense rhythm and concentration, monotony and low autonomy.

Evaluation of musculoskeletal discomfort using item response theory: creation of a scale based on the self-reported pain symptoms

This study aims to build a scale for musculoskeletal discomfort based on the self-reported musculoskeletal pain by individuals. For this, methods such as factorial analysis and item response theory were used. A sample of 1821 workers of a footwear industry participated in this study. The scale consists of four levels ranging from mild to maximum discomfort. In mild discomfort (level 60), pain symptoms are rare or frequent in regions such as cervical and trapezoidal area, low back, shoulders, wrists, ankles and feet. At level 70, rare or frequent symptoms affect regions of the upper and lower limbs. At level 80, frequent symptoms become common in the trunk and in most of the upper and lower limbs. At level 90, the symptoms become daily in elbows, thighs and knees. The scale showed signs of validity and proved useful for studies in ergonomics. Practitioner Summary: Methods such as factor analysis and item response theory were used to build a four-level musculoskeletal discomfort scale that can be useful to complement the screening process for workers with musculoskeletal pain. The scale shows signs of accuracy, in addition to validity and reliability. Abbreviations: WMSD: work-related musculoskeletal disorders; CTT: classic test theory; IRT: item response theory; KMO: Kaiser-Meyer-Olkin; PR: pain rarely; PO: pain often; PE: pain everyday; DIF: differential item functioning.

Examining the fatigue-quality relationship in manufacturing

A recent systematic review identified 73 empirical studies that linked human factors (HF) with manufacturing quality. Human fatigue was noted as a frequent (n = 26) issue in the HF-quality relationship - a finding that warrants closer examination. We extend this review by investigating the relationship between fatigue and manufacturing quality by identifying how fatigue has been conceptualized and measured, and we attempted to quantify their relationship. From the original database, 12 of 26 relevant studies (46%) indicated that physical fatigue was the primary contributor to observed quality deficits. There was a positive relationship between fatigue and quality deficits, with fatigue accounting up to 42% of the variance. More studies are needed to improve the resolution, specificity, and power of these analyses. This study sheds light on the role of HF and human fatigue effects on manufacturing quality with macroergonomic implications for embedding HF aspects into design and quality assurance processes.

A Systematic Review of Occupational Health and Safety Business Cases

Business cases are arguments developed to secure management commitment and approval for investment in an intervention. This systematic review evaluated 12 experimental and quasi-experimental studies on occupational health and safety interventions (OHSI) in various settings. The search engines used in this systematic review include PubMed, CINAHL, and Scopus. A cost and benefit analysis of OHSI was completed at the organizational level in these studies. The focus of this analysis included sample, design, theoretical framework, interventional strategies, and threats to validity and outcomes. Positive returns on investment of OHSI outcomes were shown in 10 of the studies. The other two studies concluded that their chosen OHSI were not cost-effective.

A case study of the implementation of an ergonomics improvement committee in a Brazilian hospital--Challenges and benefits

This article discusses the creation of an improvement committee (IC) to implement policies aimed at improving working conditions in a public health institution in the city of São Paulo. Suggestions were proposed for future implementations of this organizational mechanism, pursuant to the presentation of the process of its formation and the main results achieved. The findings led to the conclusion that good outcomes require autonomy and support from management, and the adoption of effective measures to improve and legitimize the improvement committee's existence. Another important issue is facilitating worker involvement and creating a locus for dialog among people with different visions within the organization. Thus, two approaches converge: a top-down approach in which policies are defined and improvement actions are actually implemented based on a general outlook of the production and work system, and a bottom-up approach specific to employees who are also engaged in improvement policies and in putting them into practice. It is also possible to point out problems and opportunities arising from actual work situations to the higher levels of management. This kind of approach fits with macroergonomics, because it integrates strategy, organization and work issues. It is possible to discuss the benefits of this approach for companies and provide conditions for workers to engage effectively in these processes. In conclusion, these proposals can be considered from an emancipatory perspective, given that different actors should be able to codetermine working conditions and work content, thus directly influencing their individual and collective experiences. The support and commitment of upper management are essential elements of success in maximizing the effectiveness of this organizational approach.

Ergonomics and sustainable development in the past two decades (1992-2011): Research trends and how ergonomics can contribute to sustainable development

The need for sustainable development has been widely recognized and sustainable development has become a hot topic of various disciplines even though the role of ergonomics in it is seldom reported or considered. This study conducts a systematic survey of research publications in the fields of ergonomics and sustainable development over the past two decades (1992-2011), in order to identify their research trends and convergent areas where ergonomics can play an important role in sustainable development. The results show that 'methods and techniques', 'human characteristics', 'work design and organization', 'health and safety' and 'workplace and equipment design' are the top five frequently researched areas in ergonomics. Ergonomics has an opportunity to contribute its knowledge especially to 'industrial and product design', 'architecture', 'health and safety' and 'HCI' (especially for energy reduction issues) categories of sustainable development. Typical methodologies and general guidance on how to contribute the expertise of ergonomist to sustainable development are also discussed.

Worker evaluation of a macroergonomic intervention in a Brazilian footwear company

This article presents a macroergonomic intervention in a Brazilian footwear company and its evaluation by the workers. Using participatory ergonomics, the traditional Taylor/Ford production system was transformed into a socio-technical one and tested by 100 volunteers working during 3.5 years in a pilot production line. Multiskilling and teamwork were the major changes promoted to enlarge and enrich work and make it more flexible. The workers' evaluation pre- and post-intervention showed an increase in overall satisfaction with the work and more commitment to the results and company targets.

STATEMENT OF RELEVANCE

This study showed that problems and solutions can be identified through participatory ergonomics, that it is easier to involve workers than the managerial staff, and that a macroergonomic intervention, mainly focusing on work organization, led to positive personnel, health and production outcomes, despite management's resistance to changes.