Keiretsu is understood as economic organisation in Japan and as a source of strength for the Japanese business in the international market. However, there existed a lot of diversity on the definition of keiretsu among economists and sociologists. Further the concept of keiretsu is scarcely on the issue in studies. By focusing on the use of a linguistic approach, the thesis explored the concept and definition of keiretsu. Keiretsu as economic organisation is essentially the embodiment of core values, trust and dependence, in social relations in Japan. Keiretsu as such is applied to a vertical keiretsu, the major support industry, the kanagata (die and mould) industry. As a result, a model of keiretsu is hypothesised. It is found that this model is applicable for analysis of the Irish toolmaking industry in terms of management. The model is useful to show the intrinsic difference of industrial structure and management between two countries in terms of die and mould making industry.