Increasing manufacturing throughput using theory of constraints methodology and lean manufacturing tools

Abstract

Companies always strive for an increase in profit by optimizing their production system. This has become possible with the application and use of certain tools and methodologies. This study analyses the actual production system for one product. Production parameters such as throughput, cycle time, inventories in the production process, and idle time were investigated. This research paper is based on achieving two different goals. The first goal is to reduce production costs while maintaining the same production capacity. The second goal is to increase production capacity. The Lean Manufacturing methodology enabled the elimination of identified waste in the production system. The elimination of waste directly affects the reduction of production costs. A more suitable layout of the production line was created, which reduces unnecessary movements. By Load Balancing, a reduction in the number of operators was achieved. One of the key elements of Lean Manufacturing, in addition to continuous improvement, is the respect of employees as key figures in product development. Therefore, the analysis also went in the direction of making production easier for employees. The Theory of Constraints (TOC) methodology was applied to investigate and analyse possible measures to reduce the observed bottleneck of the system or completely remove that bottleneck in order to increase production capacity. TOC steps are: identification of the constraint, constraint exploitation, subordination and synchronization of the constraint, the elevation of the performance, and repetition of the process with the aim of continuous improvement. In order to increase production capacity and reduce inventory between operations, the implementation of One-piece flow was analysed. With the Lean Manufacturing tools and Theory of Constraints methodology, the steps to achieve optimization were described and three solutions were offered for the Case Study. The first solution resulted in a cost reduction of €60,000 per year for the same production capacity. The other two solutions offered increases in production capacity by 21.62% and 46.15%.