The role of human-at-work systems in business sustainability: perspectives based on expert and qualified production workers in a manufacturing enterprise

A community of highly qualified employees is desirable for the workforce to become a competitive business advantage, improving and sustaining corporate health. Currently, the scientific literature is limited on information comparing the assessment of expert and qualified workers for the employee–work environment interface. Such information would be valuable for industrial managers to obtain and act on the different perspectives of its workers for business improvement and survivability. A primary objective of this study is to explore the perspectives of expert and qualified workers on the quality of the employee–work environment interface in a manufacturing enterprise. This investigation was performed in a production department in a small manufacturing enterprise. Two expert workers participated in the study, with each being in the company for 30 years and having performed all jobs in the production department as well as supervisory and line management responsibilities. A total of 13 qualified workers from day and night shifts were used in the study, with the great majority of workers possessing 10 or more years of on-the-job experience but not acquiring the same specialised knowledge required for operating the technological resources in the department. The work compatibility methodology was used to assess the quality of employee–work environment interface for both expert and qualified workers. Both expert and qualified workers provided similar trends in terms of their compatibility assessment of experienced and acting work domains. In general, the compatibility levels for the day shift were poorer than those obtained for the night shift for acting work domains. The similarities in assessment between the expert and qualified workers were much closer for factors impacting job performance at the task and immediate surrounding levels (i.e. physical and mental task content, physical environment). There were greater differences at the macro level, that is, at the process and enterprise levels, in terms of organisational/social/technological environment. This is particularly noted for the organisational environment. The compatibility values obtained for the experienced domains mirror those obtained for acting domains. The overall workload was assessed as requiring major redesign during the day shift and needing added responsibilities for the night shift according to both expert and qualified workers. The assessment of qualified workers is comparable with that of expert workers for the job content and immediate surroundings. Differences are more observed for process- and enterprise-based factors; thereby, providing company management different perspectives in order to devise organisational strategies conducive for optimum human and corporate health and pointing to the probable interactions of the different systems impacting individual and enterprise performance.

Statement of Relevance: This research examines similarities and differences between qualified and expert workers in their assessment of the worker–work environment interface. The contribution to improved understanding of the complex interactions of human-at-work and enterprise systems should be beneficial to organisations in their quest to remain competitive in a global economy.     

Computer‐Aided Ergonomic Analysis for Assembly Unit of an Agricultural Device

In many applications, those who work on assembly processes are required to work in nonergonomic stances. Incorrect positions may cause strain and persistent problems. In addition, strain in workers’ bodies also has a negative effect on labor productivity. Ergonomics should be applied to avoid this kind of negative impact on workers’ health as well as productivity. Ergonomics introduces the basic principles of system productivity and human‐machine‐environment relationship. With a series of computer‐aided ergonomics analysis (CAEA), necessary precautions can be taken in advance by determining the undesirable stances. Through CAEA, productivity for machinery and comfort for people can be ensured by creating an efficient working environment without causing health problems for workers who work in production. In this study, in an agricultural equipment producing company, current working positions of a worker carrying out tasks during the assembly of wheel hay rakes, have been evaluated via the CATIA Ergonomic Analysis Module. On the basis of the results, the design of the assembly unit was ergonomically improved. As a result of the improvement in the working environment, unfavorable stance positions were avoided and production time was decreased by 60%.     

Determinants of business sustainability: An ergonomics perspective

There is a need to integrate both macro- and micro-ergonomic approaches for the effective implementation of interventions designed to improve the root causes of problems such as work safety, quality and productivity in the enterprise system. The objective of this study was to explore from an ergonomics perspective the concept of business sustainability through optimising the worker–work environment interface. The specific aims were: (a) to assess the working conditions of a production department work process with the goal to jointly optimise work safety, quality and quantity; (b) to evaluate the enterprise-wide work process at the system level as a social entity in an attempt to trace the root causes of ergonomic issues impacting employees throughout the work process. The Work Compatibility Model was deployed to examine the experiences of workers (that is, effort, perceived risk/benefit, performance and satisfaction/dissatisfaction or psychological impact) and their associations with the complex domains of the work environment (task content, physical and non-physical work environment and conditions for learning/growth/development). This was followed by assessment of the enterprise system through detailed interviews with department managers and lead workers. A system diagnostic instrument was also constructed from information derived from the published literature to evaluate the enterprise system performance. The investigation of the production department indicated that the stress and musculoskeletal pain experienced by workers (particularly on the day shift) were derived from sources elsewhere in the work process. The enterprise system evaluation and detailed interviews allowed the research team to chart the feed-forward and feedback stress propagation loops in the work system. System improvement strategies were extracted on the basis of tacit/explicit knowledge obtained from department managers and lead workers. In certain situations concerning workplace human performance issues, a combined macro–micro ergonomic methodology is essential to solve the productivity, quality and safety issues impacting employees along the trajectory or path of the enterprise-wide work process. In this study, the symptoms associated with human performance issues in one production department work process had root causes originating in the customer service department work process. In fact, the issues found in the customer service department caused performance problems elsewhere in the enterprise-wide work process such as the traffic department. Sustainable enterprise solutions for workplace human performance require the integration of macro- and micro-ergonomic approaches.     

Determinants of business sustainability: an ergonomics perspective

There is a need to integrate both macro- and micro-ergonomic approaches for the effective implementation of interventions designed to improve the root causes of problems such as work safety, quality and productivity in the enterprise system. The objective of this study was to explore from an ergonomics perspective the concept of business sustainability through optimising the worker-work environment interface. The specific aims were: (a) to assess the working conditions of a production department work process with the goal to jointly optimise work safety, quality and quantity; (b) to evaluate the enterprise-wide work process at the system level as a social entity in an attempt to trace the root causes of ergonomic issues impacting employees throughout the work process. The Work Compatibility Model was deployed to examine the experiences of workers (that is, effort, perceived risk/benefit, performance and satisfaction/dissatisfaction or psychological impact) and their associations with the complex domains of the work environment (task content, physical and non-physical work environment and conditions for learning/growth/development). This was followed by assessment of the enterprise system through detailed interviews with department managers and lead workers. A system diagnostic instrument was also constructed from information derived from the published literature to evaluate the enterprise system performance. The investigation of the production department indicated that the stress and musculoskeletal pain experienced by workers (particularly on the day shift) were derived from sources elsewhere in the work process. The enterprise system evaluation and detailed interviews allowed the research team to chart the feed-forward and feedback stress propagation loops in the work system. System improvement strategies were extracted on the basis of tacit/explicit knowledge obtained from department managers and lead workers. In certain situations concerning workplace human performance issues, a combined macro-micro ergonomic methodology is essential to solve the productivity, quality and safety issues impacting employees along the trajectory or path of the enterprise-wide work process. In this study, the symptoms associated with human performance issues in one production department work process had root causes originating in the customer service department work process. In fact, the issues found in the customer service department caused performance problems elsewhere in the enterprise-wide work process such as the traffic department. Sustainable enterprise solutions for workplace human performance require the integration of macro- and micro-ergonomic approaches.     

Mixed model assembly line design in a make-to-order environment

Mixed model assembly lines can be found today in many industrial environments. With the growing trend for greater product variability and shorter life cycles, they are replacing the traditional mass production assembly lines. In many cases, these lines follow a ‘make-to-order’ production policy, which reduces the customer lead-time, and is expressed in a random arrival sequence of different model types to the line. Additional common characteristics of such mixed model lines in a make-to-order environment are: small numbers of work stations, a lack of mechanical conveyance, and highly skilled workers. The design problem of mixed model assembly lines in a make-to-order environment is addressed in this paper. A mathematical formulation is presented which considers the differences between our model and traditional models. A heuristic that minimizes the number of stations for a predetermined cycle time is developed consisting of three stages: the balancing of a combined precedence diagram, balancing each model type separately subject to the constraints resulting from the first stage, and a neighborhood search based improvement procedure.     

Manufacturing assembly serial and cells layouts impact on rest breaks and workers’ health

Rest breaks are necessary for workers to avoid and/or recover from overall fatigue and to preserve their health. The type of assembly layout, either in lines or in cells, is a determining factor for organizing work at manufacturing companies, and it could also influence workers' work break and microbreak times. This study aimed at evaluating rest breaks in serial and cell assembly layout configurations as well as the layout's influence on workers' health. One hundred and twenty workers from a large automobile industry, divided into two groups (series and cells), were measured for their cycle-times and break times through biomechanical exposure analysis and questionnaires to evaluate the behaviors, physical, cognitive, and mental health. The Kolmogorov-Smirnov test was used to verify the distribution of the data with a significance level of p < 0.05. The cell assembly-line layouts had the greatest cycle-time and break time, and the workers had a higher level of physical activity (p < 0.05). The serial assembly-line layouts did not generate major occupational risk, need for rest, reduced capacity for work, or higher levels of stress for the workers. The production layouts differed in relation to the cycle-times for just-in-time manufacturing, but there was no difference in relation to the production demands and to the workers' health.Relevance to industryWhen taken at appropriate times, rest breaks in the workplace can improve workers’ overall health and productive performance, which reduces healthcare costs and improves industrial productivity.     

Human‐computer interaction and lean production: The shop floor example

The approach in industrial engineering to computer‐integrated manufacturing (CIM) proved not to be the concept needed for the majority of German companies. At the moment, lean production is the focal point of discussion about production engineering. It tries to combine concepts such as human‐centered organization, internationalization of business, decentralization of decisions, increased development times, total quality management, and process‐oriented business management. There are a variety of implementation areas for lean production. One implementation has been the shop floor‐oriented production support concept as developed by the Fraunhofer Institute IAO in Stuttgart. It focuses on functions such as Computer Numeric Control (CNC) machine tool programming, shop floor control, quality assurance, and resource management, and it aims at decentralized work organization, comprehensive work contents, and support for highly skilled workers on the shop floor. This support is provided by Information Technology (IT) systems that follow the ideas of work enrichment and work enlargement, and use a so‐called shop floor metaphor and graphical user interfaces with standard tool kits. In this way, the shop floor‐oriented production support concept represents a future concept that takes into consideration particularly human factors and human‐computer interaction.     

Assembly line balancing and group working: A heuristic procedure for workers’ groups operating on the same product and workstation

In this paper, we examine an assembly line balancing problem that differs from the conventional one in the sense that there are multi-manned workstations, where workers’ groups simultaneously perform different assembly works on the same product and workstation. This situation requires that the product is of sufficient size, as for example in the automotive industry, so that the workers do not block each other during the assembly work. The proposed approach here results in shorter physical line length and production space utilization improvement, because the same number of workers can be allocated to fewer workstations. Moreover, the total effectiveness of the assembly line, in terms of idle time and production output rate, remains the same. A heuristic assembly line balancing procedure is thus developed and illustrated. Finally, experimental results of a real-life automobile assembly plant case and well-known problems from the literature indicate the effectiveness and applicability of the proposed approach in practice.     

Impact of Lean Production on Perceived Job Autonomy and Job Satisfaction: An Experimental Study

Previous studies have indicated positive and negative effects of lean production on employees’ perceived work characteristics and job attitudes. The most detrimental consequence of lean production is a decrease in the perceived job autonomy of workshop employees. To reduce these negative consequences, we propose human resource practices for integration with lean production. Drawing on the job characteristics model, we hypothesized that the implementation of lean production combined with human resource practices would enhance perceived job autonomy, job satisfaction, and operational performance. To evaluate our hypotheses, we used an experimental design consisting of a simulation game that mimics a manufacturing company. We implemented lean production combined with human resource practices in this simulated company. The results indicated a significant increase in perceived job autonomy, job satisfaction, and operational performance. Moreover, the results revealed a positive relationship between job satisfaction and operational performance.     

The Work Compatibility Improvement Framework: an integrated perspective of the human-at-work system

The industrial revolution demonstrated the limitations of a pure mechanistic approach towards work design. Human work is now seen as a complex entity that involves different scientific branches and blurs the line between mental and physical activities. Job design has been a traditional concern of applied psychology, which has provided insight into the interaction between the individual and the work environment. The goal of this paper is to introduce the human-at-work system as a holistic approach to organizational design. It postulates that the well-being of workers and work outcomes are issues that need to be addressed jointly, moving beyond traditional concepts of job satisfaction and work stress. The work compatibility model (WCM) is introduced as an engineering approach that seeks to integrate previous constructs of job and organizational design. The WCM seeks a balance between energy expenditure and replenishment. The implementation of the WCM in industrial settings is described within the context of the Work Compatibility Improvement Framework. A sample review of six models (motivation-hygiene theory; job characteristics theory; person-environment fit; demand-control model; and balance theory) provides the foundation for the interaction between the individual and the work environment. A review of three workload assessment methods (position analysis questionnaire, job task analysis and NASA task load index) gives an example of the foundation for the taxonomy of work environment domains. Previous models have sought to identify a balance state for the human-at-work system. They differentiated between the objective and subjective effects of the environment and the worker. An imbalance between the person and the environment has been proven to increase health risks. The WCM works with a taxonomy of 12 work domains classified in terms of the direct (acting) or indirect (experienced) effect on the worker. In terms of measurement, two quantitative methods are proposed to measure the state of the system. The first method introduced by Abdallah et al. (2004) identifies operating zones. The second method introduced by Salem et al. (2006) identifies the distribution of the work elements on the x/y coordinate plane. While previous efforts have identified some relevant elements of the systems, they failed to provide a holistic, quantitative approach combining organizational and human factors into a common framework. It is postulated that improving the well-being of workers will simultaneously improve organizational outcomes. The WCM moves beyond previous models by providing a hierarchical structure of work domains and a combination of methods to diagnose any organizational setting. The WCM is an attempt to achieve organizational excellence in human resource management, moving beyond job design to an integrated improvement strategy. A joint approach to organizational and job design will not only result in decreased prevalence of health risks, but in enhanced organizational effectiveness as well. The implementation of the WCM, that is, the Work Compatibility Improvement Framework, provides the basis for integrating different elements of the work environment into a single reliable construct. An improvement framework is essential to ensure that the measures of the WCM result in a system that is adaptive and self-regulated.     

Mapping workers’ performance to analyse workers heterogeneity under different workflow policies

Manual work in assembly lines allows one to benefit from human reasoning capabilities and to assure the flexibility to adapt to fluctuations in production volume, products mix and reduced product lifecycles. With the objective of quantifying and systematizing the knowledge about the heterogeneity of workers’ performance, data was collected in an industrial setting. The results demonstrate a significant variation in workers’ performance in terms of speed and variability of the task completion time. A mapping approach is proposed aiming to quantify the workers’ performance and visualize performance patterns. Since the human performance is influenced by the setting where the workers perform their job, two real assembly line pacing mechanisms were set and studied: pacing derived from the manual assembly system rhythm and pacing imposed by a fixed time constraint. The type of pacing clearly influences workers’ performance (i.e., speed and variability) and revealed a significant influence in the assembly line output. In particular, imposing a fixed and equal time constraint for every worker reduces the heterogeneity of workers’ performance and improves the assembly line output.     

Digital twin-enabled Graduation Intelligent Manufacturing System for fixed-position assembly islands

The layout of fixed-position assembly islands is widely used in the heavy equipment industry, where the product remains at one assembly island for its entire assembly period, while required workers, equipment, and materials are moved to the island according to the assembly plan. Such layout is not only suitable for producing bulky or fragile products, but also offers considerable flexibility and competitive operational efficiency for products with medium variety and volumes. However, due to inherent complexity of the product, sophisticated assembly operations heavily rely on skilled operators, and the complexity and uncertainty are high and amplified by such massive manual interventions as well as the unique routing patterns of the fixed-position assembly process. Aiming at reducing the complexity and uncertainty, this paper introduces a digital twin-enabled Graduation Intelligent Manufacturing System (DT-GiMS) for fixed-position assembly islands. Inspired by the success of graduation ceremony, an assembly system-Graduation Manufacturing System (GMS) is proposed for fixed-position assembly islands, in which job tickets, setup tickets, operation tickets, and logistics tickets are designed to organize the production activities. Following the concept of digital twin, unified digital representations with appropriate sets of information are created at object level, product level, and system level, respectively. Through Internet of Things (IoT), smart gateway, Web 3D and industrial wearable technologies, vital information including identity, status, geometric model, and production process can be captured and mapped in physical space, and converged and synchronized with their digital representations in twin (cloud) space on a real-time basis. The overall framework of DT-GiMS is presented with physical layer, digital layer, and service layer. Real-time convergence and synchronization among them ensure that right resources are allocated and utilized to the right activities at the right time with enhanced visibility. Considering customer demand and production capacity constraints, real-time ticket pool management mechanisms are proposed to manage production activities in a near-optimal way under DT-GiMS. With the support of cloud-based services provided in service layer in DT-GiMS, managers could easily make production decisions, and onsite operators could efficiently complete their daily tasks with nearly error-free operations with enhanced visibility. A demonstrative case is carried out to verify the effectiveness of the proposed concept and approach.     

A corporate workplace model for ergonomic assessments and improvements

Several companies have developed their own company-specific models for ergonomic improvements. This study aims to describe and identify factors supporting and hindering the implementation and application of one such corporate model for ergonomic assessment and improvement. The model has been developed by Volvo Car Corporation and implemented at an assembly plant in G?teborg, Sweden. The model is unique as it is intended to be used by production engineers and safety representatives in cooperation. The process for assessment of musculoskeletal risks is standardised and participatory, which also supports identification of solutions. Interviews, questionnaires, observation and document studies were used to evaluate the use of the model. The model was found to improve participation and collaboration among stakeholders; provide a more effective ergonomic improvement process; visually represent the ergonomics situation in the company; and give legitimacy to and awareness of ergonomics. However, the model was found to be rather resource demanding and dependent on support from management and unions. In particular, a substantial training programme and regular use of the model are needed.     

Fuzzy logic based method to measure degree of lean activity in manufacturing industry

Lean manufacturing is gaining popularity as an approach that can achieve significant performance improvement in the industry. However, the application of lean manufacturing is not an easy process. To reach the level of full implementation of lean manufacturing takes a long time and during that time the continuous improvement must be made. In the process of continuous improvement, lean manufacturing assessment is required. One form of assessment is to measure the degree of lean implementation. However, it is the complexity involved in the measure of degree of leanness. This complexity arises due to (a) the inherent multi-dimensional concept of leanness (b) unavailability manufacturing practice database that can be used as a benchmark in assessing the degree of leanness and (c) the necessity for the application of subjective human judgement on lean practices which involve vagueness and bias due to variation of evaluator's knowledge and experience. In this paper a method to deal with the multi-dimensional concept, unavailability benchmark and uncertainty, which arises from the subjective and vague human judgement for the measurement of degree of leanness, is proposed. The multi-dimensional concept involving a variety of components of lean practices is measured in order to arrive at a measure for the lean activity of a given organization. It is constructed from primary and secondary data involving a comprehensive literature review and validated with interviews with a set of sample organizations representing the entire spectrum of the industry. The vagueness of subjective human judgement on degree of application of lean practices is modelled by fuzzy number in conjunction with an additional consideration related to the length of lean practice implementation and the use of multi-evaluators. Value stream mapping is used in scoring the degree of implementation of lean so the use of benchmark is not necessary. Some results from an initial survey from a sample of respondents from the manufacturing industry in Indonesia are presented to illustrate the applicability and potential strength of the proposed method.     

Task design, psycho-social work climate and upper extremity pain disorders--effects of an organisational redesign on manual repetitive assembly jobs.

A company redesign was carried out to improve production efficiency and minimise the prevalence of work-related musculoskeletal disorders and sick leave. The redesign was evaluated on the basis of studies of assembly workers before (17 workers) and after (12 workers) the redesign. The redesign resulted in more varied, less repetitive, and more autonomous assembly jobs. The psycho-social work climate was both improved and impaired. A medical examination showed that eight of 17 workers before and nine of 12 workers after the redesign suffered from upper extremity pain disorders. Neither the production goals nor the goals of the redesign were fulfilled. Our conclusion was that the increased task variation and impaired psycho-social work climate, combined with a lack of skill and competence, actually increased the physical stress, risk for disorders and difficulties in fulfilling the production goals.     

Towards successful physical stress reducing products: an evaluation of seven cases

Lifting, carrying, pushing and pulling at work are assumed to be related to increased risks of musculoskeletal injury, mainly in the low back and shoulder region. The implementation of products to reduce the physical load in heavy work is a well-known strategy to attack this problem. The success of these products depends not only on the product itself, but also on the process of product development and implementation. In this paper, seven cases are described where products have been developed to reduce the physical load on scaffolders, bricklayers, bricklayer's assistants, roofworkers, aircraft loaders, glaziers and assembly line workers. These products are described with special reference to the physical load problem in the occupational task, the process of product development, the nature of the product, the potential effects on physical load and the opinion of workers. From these cases, a list of key factors in product development contributing to the success of a product is composed. These concern among others a direct participation of workers, a wide analysis of risks, an analysis of potential negative side effects, and a systematic stepwise approach.     

Self‐managed work teams and manufacturing strategies: Cultural influences in the search for team effectiveness and competitive advantage

This article examines the relationship between manufacturing strategy and self‐managed work teams. The implementation of team working and lean production as a strategy designed to improve competitive advantage is juxtaposed with the cultural influences utilizing Hofstede's (1980) model of cultural dimensions. Case study material illustrates the contrasting positions posed by the different cultural and philosophical bases of lean production and self‐managed work teams. The resulting disequilibrium may explain why the implementation of teams in Western environments has proved less successful than anticipated in the manufacturing context. © 2001 John Wiley & Sons, Inc.     

A sequencing problem for a mixed-model assembly line in a JIT production system

In an assembly line of a just-in-time (JIT) production system, workers have the power and the responsibility to stop the line when they fail to complete their operations within their work zones. This paper deals with a sequencing problem for the mixed-model assembly conveyor line in the JIT production system. In some environment, the most important criterion is the line stoppage rather than the variation of production rates. The problem is to find an optimal sequence of units that minimizes the total line stoppage time. Lower and upper bounds of the total line stoppage time are derived and the branch-and-bound method is applied to the problem. A numerical example is given.     

A heuristic approach for U-shaped assembly line balancing to improve labor productivity

The assembly line balancing problem is a non deterministic polynomial type planning problem for mass production. Layout design changes constitute a major decision that yields investment for assembly operations and numerous heuristics have been reported in the literature for solving the line balancing problems. U-shaped assembly layout offers several benefits over traditional straight-line layout in implementation of lean manufacturing and Just-In-Time technology. In the paper an attempt has been made to evaluate labor productivity in U-shaped line system and straight line system. A Critical Path Method (CPM) based approach for U-shaped assembly line has been applied for assigning the task to the work stations for assembly line layout. Results show that the CPM based U-shaped approach performs better and improve the labor productivity of assembly line layout.