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Manufacturing ergonomics refers to the application of ergonomic principles and human factors analysis to the design of manufacturing tasks with the final aim to optimize the workers’ wellbeing and guarantee the expected process performance. Traditional design approaches are based on the observation of individual workers performing their jobs, the detection of unnatural postures (e.g., bending, twisting, overextending, rotating), and the definition of late corrective actions according to ergonomic guidelines. Recently, computer-integrated simulations based on virtual prototypes and digital human models (DHMs) can be used to assess manufacturing ergonomics on virtual manikins operating in digital workplaces. Such simulations allow validating different design alternatives and optimizing the workstation design before the creation, and pave the way to a new approach to manufacturing system design. The present paper aims at comparing different computer-integrated set-ups to support the design of human-centred manufacturing workstations. It defines a protocol analysis to support workstation design by analysing both physical and cognitive aspects, and applies the protocol within different digital set-ups. In particular, the study investigates a 2D desktop set-up using standardized DHMs and a 3D immersive mixed reality set-up based on motion capture of real workers’ acting into a mixed environment, comparing them with the traditional approach. An industrial case study focusing on design optimization of a manufacturing workstation in the energy industry is used to test the effectiveness of the two digital set-ups for the definition of re-design actions.

Today manufacturing enterprises aim not only to deliver high-value, cost-effectively products in a sustainable way, but also to consider the quality of the working environments. The analysis of human factors, which strongly affect time and quality of manufacturing processes, are crucial for satisfying people involved in the manufacturing process and making them safe, preventing diseases, errors and excessive workload. The paper presents a structured procedure to automatically extract data from virtual analysis made by digital manufacturing tools and measure a set of indicators to validly assess manufacturing ergonomics. The research considers the state of the art in manufacturing ergonomics and defines a set of indicators suitable for manufacturing manual operations, focusing on assembly tasks. Furthermore, it defines a methodology to automatically extract data valorising the selected indicators and an application, based on Visual Basic, to generate the specific task list and related assessment. The result is a rapid and objective assessment, independent from the experience of the user, which can be executed during process design. The procedure has been applied to an industrial case study, where the manual assembly of cabin supports on the tractor chassis has been analysed in order to correct the most uncomfortable steps and obtain a more ergonomic process. A decrease of the EAWS score, calculated with the proposed method, allowed to validate the proposed solution, suggesting a redesign of the assembly cycle to improve the working conditions. Such a procedure anticipates the analysis of the workers’ wellbeing during the design stage to support the definition of human-centric manufacturing processes, simplifying and accelerating the assessment activities.

Sustainable Manufacturing (SM) traditionally focused on optimization of environmental and economic aspects, by neglecting the human performance. However, the industrial plant's costs, productivity and process quality highly depend on the individual human performance (e.g., comfort perceived, physical and mental workload, simplicity of actions, personal satisfaction) and how much hazardous positions and uncomfortable tasks finally cost to the company. The present paper defines a human-centred virtual simulation environment to optimize physical ergonomics in workstation design and demonstrates its benefits on an industrial case study in pipe industry. The proposed environment aims at overcoming traditional approaches, where analysis are carried out at the shop-floor when the plant is already created, by providing a virtual environment to easily test and verify different design solutions to optimize physical, cognitive and organizational ergonomics.