Over the last decade, a rapid development of internet, wireless mobile telecommunication, and product identification technologies make whole product life cycle visible and controllable, which can improve several operational issues over the whole product life cycle: product design improvement, predictive maintenance, rational decision on end-of-life products, and so on. The key element to solve these issues is to assess the degradation status of a product based on gathered data during product usage period. However, despite its importance, due to the interrupted information flow of the product life cycle after product sales, it has not received enough attention in the literature until now. To overcome this limitation, this study develops a decision support method, called degradation mode and criticality analysis (DMCA), for the analysis of product degradation status based on gathered product usage data. The proposed method enables us to identify and assess the degradation status of a product and give a suitable guide for the next action. To show the effectiveness of the proposed approach, a case study for a heavy construction equipment vehicle is introduced.