The study reported in this paper highlights, through a case study, the benefits of using an integrated operations management approach, through the use of lean/simulation/ergonomics concepts, to improve productivity and ergonomics. The study focuses on the packaging production area of a metallurgical plant and, in particular, a given product family. The Strain Index (SI) was the chosen method to evaluate the ergonomic situation derived from forceful hand exertions and a simulation model was developed in order to evaluate the “best” layout. Lean manufacturing tools such as Value Stream Mapping (VSM) and Poka Yoke were also used to analyze and increase productivity by eliminating several wastes. Through the automatization of manual tasks, the implementation of job rotation and the change of the process layout to a cellular configuration, it was possible to increase productivity by about 136% and considerably improve ergonomic conditions. This study shows that ergonomic condition improvements should be considered as a means to increase productivity. In fact, improvements made in ergonomic conditions can contribute very positively towards productivity increases. The proposed method can be replicated in other production areas as well as other manufacturing sectors, proving a valuable tool for researchers and practitioners.