Abstract. Smart environments include context-aware computing to enhance system capabilities which affect user interaction positively. A context-aware application should collect contextual information through different ways depending on technology availability and handle this information adequately to execute actions or warnings, present information or modify the environment. Ambient intelligence (AmI) habitually means system complexity and heterogeneity. This paper describes an AmI system case-study, developed for the Easy Line + project, a decentralized intelligence carefully structured in agents grouped by roles in domains to improve system package interaction and integration. The main purposes for this implementation are: avoid complexity and inconsistence between the elements of the system and increase system