Proposal of an innovative ergonomic SMED model in an automotive steel springs industrial unit

Faced with globalization, high competition, and the demands of a market in constant dynamism, companies strive to adopt measures for increasing their productivity, among which Lean Manufacturing stands out. Although this set of strategies allows optimizing the production by reducing waste, the literature review showed that, in several organizations, the implementation of Lean does not reflect positive impacts on productivity. It is frequently related to the superficial nature of the approach: the tools and methods are applied, but the repercussions on the workers are commonly neglected. In response, companies seek to implement Risk Management policies to assess injury risk factors for operators during task execution. This study highlights the importance of integrating Lean Manufacturing and Ergonomics principles into organizations to increase productivity and improve working conditions simultaneously. Therefore, by identifying improvement opportunities using the VSM tool, this work aims to implement an innovative and systematic intervention model, which enables the integrated application of Single-Minute Exchange of Dies (SMED) and ergonomic analysis in a metallurgical factory. To this end, the innovative Ergonomic SMED (ESMED) Model is proposed, comprising six steps, which, in this study, focus on the setup operations of a molding machine and by including Rapid Upper Limb Assessment (RULA), Rapid Entire Body Assessment (REBA), Job Strain Index (JSI), Key Indicator Methods (KIM), and Shoaf's Model methods. Based on the results obtained, it is possible to evidence the usefulness and effectiveness of the proposed model in this scenario, emphasizing the 55% reduction in setup time and the extreme attenuation of the level of Work-Related Musculoskeletal Disorders (WMSDs) risk in workers.