Assessment of Overall Equipment Effectiveness (OEE) for marble manufacturing process: a case study

Typical problems arising in the manufacturing industry, e.g. equipment breakdown, repair, and quality defects, have a great effect on the quality, cost and delivery time of goods. In this framework, the Overall Equipment Effectiveness (OEE) represents an important measure tool which involves the process of monitoring the availability, performance, and quality of manufacturing equipment and facilities. The performance evaluation measures of the three OEE factors give information about decisions and tasks which should be implemented to improve productivity and profitability. This paper investigates the efficiency loss of a marble manufacturing process aiming at identifying the root causes of bottlenecks operations to improve its system performance in terms of OEE and productivity. The OEE values are assessed over ten weeks, by considering four different processing cycles of the marble production: the block sawing process which consists in two sub-processes (slabs and tiles production), the polishing process and the resin treatment process. The types of potential equipment losses in OEE, as well as the factors availability, utilization, speed, quality, and planned stop time are identified for each processing cycle considered, to analyze how each OEE section impacts the overall OEE. From the empirical findings, operational performance efficiency losses are found to have the largest influence on OEE. Based on the results, improvement potentials and future tasks are identified to provide useful pieces of information for the decision-making when looking for the improvement of such a productivity indicator, including a preliminary economic assessment.