Changes in domestic family structure, increased life expectancy, and prevalence of chronic diseases and dysfunction have led to a concomitant increase in care needs. This study examines the use of the ECare management system as a service by long-term care institutions using "Service Experience Engineering" theory and "Innovation Net" stage service modeling through contextual inquiry. Data was gathered from the subject service users, observation, and interactive interviews through the five dimensions (activities, environments, interactions, objects, users). For the ECare management system, an aggregate behavior model was constructed to analyze user behavior and potential needs. An affinity diagram was used to discover hidden service needs that could be useful to the creation of new service opportunities. The results of the study are: (1) ECare management system users encountered smart mobile devices, operating systems, system design, personal factors, the influence of others, and external factors; (2) A basis for future service design can be formed by i) aggregating ECare management system service demand, ii) improving system functionality and increasing job project, iii) user self-adjustment and strengthening of information capabilities, iv) investments in long-term care institutions, v) recruitment of professionals for industry cooperation and common development, and vi) unification of government policy with system developers’ efforts.