An intelligent approach to high quantity automated machining

Purpose: To investigate the possibility of application of knowledge-based expert systems to facilitate the task of techno-economical feasibility analysis of utilization of special purpose machines for high quantity production tasks. Also, to study the possibility of assisting special purpose machine designers in applying knowledge-based expert systems in the design task in order to reduce required machine design time, improve machine design efficiency, and eliminate possible human errors. Design/methodology/approach: Development of a knowledge-based expert system has been proposed to help decide where to utilize special purpose machines to accomplish the production task. The knowledge-based expert system consists of a rule-base which contains qualitative human knowledge and expertise in the form of if-then rules; and a database which contains qualitative information of machining operations, and characteristics of standardized special purpose machine components. Findings: A case study has been presented where an analysis has been made on the basis of techno-economical considerations for a typical part with three machining operations to be produced in large quantities. It has been concluded that for the given production task, special purpose machines would result in a significant 59% reduction of costs compared to CNC machines, and 95.5% compared to traditional machines. The proposed methodology also reduces the time and effort needed for decision making on utilization of special purpose machines and determination of machine layout. In addition, it minimizes the level of expertise required to perform these functions and eliminates possible human errors. Research limitations/implications: The current system focuses on drilling and drilling-related operations which cover about 60% of all machining operations. More work is needed to cover other machining operations including milling. Also the KBES developed currently works on a standalone basis. Work is in progress to integrate it with a 3D CAD modelling system. Upon completion the information could be directly extracted from the CAD system, eliminating the need for manual data input by the user. Originality/value: In spite of a large number of publications on machine tool design in the literature, publications on special purpose machines are very limited. The method of techno-economical analysis presented here for utilization of special purpose machines in comparison with other production alternatives is of great value to manufacturing engineers and specialists. Also the methodology presented for machine design and implementation is highly valued by machine tool designers and manufacturers.