Dr. S. Sudhakar, International Journal of Research in Engineering, IT and Social Sciences, ISSN 2250-0588, Impact Factor: 6.452, Volume 08 Issue 2, February 2018, Page 73-77 http://indusedu.org Page 73 This work is licensed under a Creative Commons Attribution 4.0 International License Fishbone Diagram Mapping of Defects in Die Casting Unit- An Investigation of Unfilling Die Casts Dr. S. Sudhakar (Professor, AJK Institute of Management, Coimbatore, Tamilnadu, India) Abstract: The Study was made at a die moulding unit which depended on injection moulding machines to cast the aluminium mould. The main premise of the study was to help the unit to identify the defects in unfilling die cast. The study involved detailed observation of the manufacturing of die cast and noted the defects. The reasons for unfilling dies cast was identified and explained to the production unit managers by means of a fishbone diagram. Keywords: Fishbone diagram, Ishikawa diagram, Die casting machines, unfilling parts and hot chamber machines I. INTRODUCTION In this age of accelerated technological development, a lot of businesses are using various time tested as well as latest analysis tools in their operations. The main aim of these analysis tools is to help the managers to uncover the key concerns of business and take corrective course for continuous improvement of various business processes. Though an old and time tested tool, Fishbone analysis is here to stay and used by operations management managers in the factories. The Fishbone diagram (also called the Ishikawa diagram) is a tool for identifying the root causes of quality problems. It was named after Kaoru Ishikawa, a Japanese quality control statistician, the man who pioneered the use of this chart in the 1960's (Juran, 1999). The Fishbone diagram is an analysis tool that provides a systematic way of looking at effects and the causes that create or contribute to those effects. Because of the function of the Fishbone diagram, it may be referred to as a cause-and-effect diagram (Watson, 2004).It is considered one of the seven basic tools of quality management along with the histogram, Paretochart, check sheet, control chart, flowchart and scatter diagram. It is known as a fishbone diagram because of its shape, similar to side view of a fish skeleton. The purpose of drawing a Fish Bone diagram is to arrive at a few key sources that contribute most significantly to the problem being examined. These sources are then targeted for improvement. The diagram also illustrates the relationships among the wide variety of possible contributors to the effect. The Ishikawa diagram, like most quality tools, is a visualization and knowledge organization tool. Simply collecting the ideas of a group in a systematic way facilitates the understanding and ultimate diagnosis of the problem. Several computer tools have been created for assisting in creating Ishikawa diagrams. A tool created by the Japanese Union of Scientists and Engineers (JUSE) provides a rather rigid tool with a limited number of bones. Other similar tools can be created using various commercial tools. Steps to Construct the Ishigawa Diagram  Place the main problem under investigation in a box on the right.  Have the team generate and clarify all the potential sources of variation.  Use an affinity diagram to sort the process variables into naturally related groups. The labels of these groups are the names for the major bones on the Ishikawa diagram.  Place the process variables on the appropriate bones of the Ishikawa diagram. Combine each bone in turn, insuring that the process variables are specific, measurable, and controllable. If they are not, branch or “explode” the process variables until the ends of the branches are specific, measurable, and controllable. The Following Points have to be Noted While Constructing the Diagram  Take care to identify causes rather than symptoms.  Post diagrams to stimulate thinking and get input from other staff.  Self-adhesive notes can be used to construct Ishikawa diagrams. Sources of variation can be rearranged to reflect appropriate categories with minimal rework.  Insure that the ideas placed on the Ishikawa diagram are process variables, not special caused, other problems, tampering, etc.  Review the quick fixes and rephrase them, if possible, so that they are process variables.