Background: Provision of high-quality healthcare services to hospital patients IS regarded as an important social issue in Japan. One useful approach is to diagnose the healthcare provision process based on failure cases, including not only medical accidents but also medical incidents, to find the key factors related to the healthcare provision process, and to change the process for the better. Many previous related studies in healthcare are too focused on the-human factor," which is only one among many different types of factors. On the other hand, in the industry field, many useful analysis models such as the Input-Process-Output model, Process Networking, Quality Management System models have already been developed and applied in many companies. However, there are substantial differences among the analytic viewpoints used in each model, and the relationship among them are not clear. Purpose: To conduct proper work process diagnosis based on failure cases, the necessary analytic viewpoints must be sufficiently systematized for hospital medical staffs who are unfamiliar with the above analysis models to utilize them relatively quickly. The purpose of this study is to systematize the analytic viewpoints, establish the diagnosis procedure and develop the needed tool. Finally, we confirm the effectiveness of the proposed method by applying it in hospital A. Approach: First, we identify the necessary conditions of the ideal process model that can provide high-quality healthcare services by examining them from the viewpoint of process structure, contents and operational management style. After establishing the general diagnosis procedure based on the failure cases, the analytic viewpoint used in each step of the diagnosis is specified and shaped into one analytic template. Findings: We proposed a method for diagnosing the healthcare provision process based on failure cases and applied it in several real cases in hospital A. As a result, we can confirm that the proposed diagnosis method leads medical staffs to review their own healthcare provision process systematically, to find the key factors of the failure case effectively, and to devise various types of countermeasures compared with the previous studies.