Abstract
This paper considered merits and demerits of two methods used to categorize quality defectives and troubles in small lot production of many types of products and services in order to prevent their recurrence: a method that focuses on 3H―Hajimete (first time), Henkou (change) and Hisashi- buri (after a long time)―and a method that focuses on human aspect, and then proposed a new categorization method by integrating both methods. Moreover, it also systematized a method of planning countermeasures for enhancing weakness of preventive activities based on the categorization results. The proposed method was applied to actual quality defectives and troubles in Company A that implemented small lot production of many types of mechanical products to discuss its applicability and effectiveness. As the results, it was found that the proposed method can get categorization results that have a good correspondence to weakness of preventive activities and countermeasures for enhancing them, help more systematic planning of the countermeasures, and therefore overcome difficulties in the method that focuses on 3H.
