Proposal of an Assurance Case Description Method Considering External Environment of Systems: Application to Operation of an Ice-Skating Rink

This study aims to 1) propose an assurance case description method which allows considering simultaneously the inside of a system, and the assumed changes outside the system, and 2) evaluate whether the proposed method contributes to business improvement for the operation of a Japanese ice-skating rink run by a company. Japanese ice-skating rinks have a difficulty with year-round operation; only about 20% are open all year, during not only summer but winter. If they obtain assurance of profits as a commercial enterprise, year-round operation of ice-skating rinks will be feasible. The previous study refers to discussion using assurance cases for improving the feasibility of accomplishing management vision and management strategy. This study determines, through an interview to the ice-skating rink manager by using an assurance case, whether what are described in the assurance cases can be realized. As a result, this study visualizes what can and cannot be accomplished. Description of assumed changes in the external environment enables the user to recognize changes in the external environment. This study thereby evaluates through an interview whether the operation of the ice-skating rink can change. Finally, we conclude with future research topics.