As the business domain has been extended to mobile environment, Workflow Management System (WFMSs) need to support various services in the area. There have been several researches to support the mobile environment, but they are insufficient to apply to general WFMSs based on OMG or WfMC Model. Also the scope of disconnectable clients is too restricted. Our main idea of handling disconnected clients in WFMSs is to explicitly define disconnected operations at process build-time and to support clients with the definition at run-time. For the purpose, in this thesis, we have developed a specification method to explicitly express disconnected operations. During the course, we have also presented the concept of disconnectable tasks by analyzing the properties of tasks related to disconnection. We first specify the disconnection information and decide the sequence of run-time operations. Then we add several client / server modules to ICU/COWS in order to handle the disconnectable tasks with the information. The information set and modules developed in this thesis, extend the scope of disconnectable tasks and make it possible to apply them to general WFMSs.