Enabling condition based maintenance in a precious metal processing plant

William J. Ngoma, Paul T Mativenga, J. Pretorius
2020 Procedia CIRP  
In today's business environment, the trend towards more product variety and customization is unbroken. Due to this development, the need of agile and reconfigurable production systems emerged to cope with various products and product families. To design and optimize production systems as well as to choose the optimal product matches, product analysis methods are needed. Indeed, most of the known methods aim to analyze a product or one product family on the physical level. Different product
more » ... ferent product families, however, may differ largely in terms of the number and nature of components. This fact impedes an efficient comparison and choice of appropriate product family combinations for the production system. A new methodology is proposed to analyze existing products in view of their functional and physical architecture. The aim is to cluster these products in new assembly oriented product families for the optimization of existing assembly lines and the creation of future reconfigurable assembly systems. Based on Datum Flow Chain, the physical structure of the products is analyzed. Functional subassemblies are identified, and a functional analysis is performed. Moreover, a hybrid functional and physical architecture graph (HyFPAG) is the output which depicts the similarity between product families by providing design support to both, production system planners and product designers. An illustrative example of a nail-clipper is used to explain the proposed methodology. An industrial case study on two product families of steering columns of thyssenkrupp Presta France is then carried out to give a first industrial evaluation of the proposed approach. Abstract In precious metal processing plants, suitable maintenance systems should be deployed to provide the necessary plant operating conditions, ensure plant availability and provide critical fume extraction and filtration systems for health and safety. A key focus for this work was use of sensors to monitor and predict abnormal equipment behaviour and examining how the data obtained could be processed into information and better inform the condition monitoring systems. The requirement for this research was driven by escalating maintenance costs in an industrial case study in South Africa. Historical records on equipment failure and was used in Pareto analysis to define the critical assets and failure modes for equipment that dominated the escalating maintenance costs for the industrial case study. Vibration data from mounted sensors was then collected the identified critical assets, analysed and used to infer condition of critical assets. Statistical tools based on process capability index values for processes in control and out of control were defined for tracking system deterioration and enabling predictive maintenance. The results show that sensors and thresholds based on process capability index can be used in predictive maintenance to alert maintenance teams to attend to vacuum pumps and fans pre-failure and hence improve plant availability and operation and reduces cost. Abstract In precious metal processing plants, suitable maintenance systems should be deployed to provide the necessary plant operating conditions, ensure plant availability and provide critical fume extraction and filtration systems for health and safety. A key focus for this work was use of sensors to monitor and predict abnormal equipment behaviour and examining how the data obtained could be processed into information and better inform the condition monitoring systems. The requirement for this research was driven by escalating maintenance costs in an industrial case study in South Africa. Historical records on equipment failure and was used in Pareto analysis to define the critical assets and failure modes for equipment that dominated the escalating maintenance costs for the industrial case study. Vibration data from mounted sensors was then collected the identified critical assets, analysed and used to infer condition of critical assets. Statistical tools based on process capability index values for processes in control and out of control were defined for tracking system deterioration and enabling predictive maintenance. The results show that sensors and thresholds based on process capability index can be used in predictive maintenance to alert maintenance teams to attend to vacuum pumps and fans pre-failure and hence improve plant availability and operation and reduces cost.
doi:10.1016/j.procir.2020.04.138 fatcat:mjrcgiwntze5jpmjngek4wsewa