This work presents improvements in the communication protocol and service coordination mechanism of the HoCa architecture, a multi-agent based architecture designed to facilitate the development of pervasive systems that proposes a new model where multi-agent systems and service oriented architectures are integrated to facilitate compatible services. A coordinator agent proposes a new planning model, where the complex processes are modeled as external services. The agent acts as coordinators of Web services that implement the four stages of the case-based planning cycle. One of the main aims of the pervasive systems is to be able to adapt themselves in execution time to the changes in the number of resources available, the mobility of the users, variability in the needs of the users and failures of the system. Multiagent systems are suitable to resolve these issues due to their capabilities such as autonomy, reactivity, pro-activity, mobility, etc.