In the last decade, industrial research for sustainable development and environment has become more strategically oriented, due to increasing of environmental pressures coming from local laws, stakeholders, and final customers. The goal of this research is to create a methodical approach for integrating the development of environmental and quality audits by prioritizing corrective actions (CA). The work starts and develops within a firm that produces smartcards for mobile phones, where environmental audits have been integrated with quality audits by a fuzzy inference engine that addresses gravity determinations of environmental and quality nonconformities. The findings of this study provided some general principles to integrate environmental management system (EMS) in quality management system (QMS) development and suggested an implementation of Continuous Improvement, which addresses, analyzes, prioritizes, and measures activities within the Deming wheel.
Human pose estimation focuses on methods that allow us to assess ergonomic risk in the workplace and aims to prevent work-related musculoskeletal disorders (WMSDs). The recent increase in the use of Industry 4.0 technologies has allowed advances to be made in machine learning (ML) techniques for image processing to enable automated ergonomic risk assessment. In this context, this study aimed to develop a method of calculating joint angles from digital snapshots or videos using computer vision and ML techniques to achieve a more accurate evaluation of ergonomic risk. Starting with an ergonomic analysis, this study explored the use of a semi-supervised training method to detect the skeletons of workers and to estimate the positions and angles of their joints. A criticality index, based on RULA scores and fuzzy rules, is then calculated to evaluate possible corrective actions aimed at reducing WMSDs and improving production capacity using a collaborative robot that supports workers in carrying out critical operations. This method is tested in a real industrial case in which the manual assembly of electrical components is conducted, achieving a reduction in overall ergonomic stress of 13% and an increase in production capacity of 33% during a work shift. The proposed approach can overcome the limitations of recent developments based on computer vision or wearable sensors by performing an assessment with an objective and flexible approach to postural analysis development.
Purpose: – The aim of the present work is to provide a case study where lean production (LP) techniques are implemented in a semi-automated assembly line with O-shaped (closed-loop) layout configuration. The action research has been conducted within an assembly line for automotive components. The work aims to provide insights on the impact of loop layout features with respect to lean principles’ application; operative solutions related to some logistic limit of loop layout; and how kanban technique can be adapted to an O-shaped layout. Design/methodology/approach: – The main research methodology is based on action research within an assembly line of oil pumps. The two research questions find answer through literature analysis and implementation of LP in the O-shaped layout. In the A3 step, we identify the main weak points of a loop layout also under the perspective of operators’ feeling. The analysis of the main constraints is conducted in this step, with respect to the most common layout used within LP adoption. Steps A4 and A5 answer to RQ2 by an on-field results’ analysis. Findings: – The use of an O-shaped layout may allow to improve ergonomic conditions for workers; to better organize parts feeding through slides and chutes because of the presence of operators outside the line. The new approach to determine the number of withdrawal kanban potentially extends the findings of Tardif et al. (2012): the minimum of the objective function is reached with a higher number of withdrawal kanbans. Research limitations/implications: – The approach is applied within a stand-alone line, while in several industrial contexts, we may find several of these lines in the same shop floor. In this case, LP implementation would cope with the several kanban cards circulating, the over-saturation of the logistic operator in supplying all the lines with smaller quantities of materials. Practical implications: – The action research resulted in the introduction of a new concept of supermarket, conceived as a decoupling buffer that lies near the line and in the review feeding devices, with the adoption of bins and operators’ feeding chutes. Parts’ feeding systems is reorganized with a two levels of withdrawal kanban. The introduction of line supermarket and the change of supply policies from pallets to bins contributed to the strong reduction of average work-in-progress. Yet, the double-withdrawal kanban and the small quantities supplied may cause an increase of material handling times and meters covered by operators. Social implications: – Better working condition of the line operators because of the presence of ergonomic chutes for parts’ feeding. In contrast, we observed a high saturation of logistic operator because of the small quantities of components supplied on the line, with an increased stress of this worker. Originality/value: – A decoupled withdrawal kanban (DWK) is developed. In DWK, the first withdrawal is issued to the supermarket that serves the line. The second withdrawal kanban is issued from the supermarket to the central warehouse. Within DWK, we propose a modified dimensioning formula through minimization of the objective function Z(k). Parts’ feeding is now organized with sliding chutes on operators’ workstations to collect components in accordance to kanban dimensioning.
1 December 2014 in International Journal of Hydrogen Energy