The coordination of concurrent activities in collaborative environments is a very important and difficult task. Many approaches for the construction of large-scale flexible group-ware applications there exist in the literature. They provide valid support to modelling, analysis and to a white-box developing of coordination protocols for computer supported cooperative applications. Little attention has been dedicated so far to group-ware applications built by assembling third-party components. In this paper by means of an explanatory example, we apply a software architecture based approach to the group-ware systems development. The software architecture imposed on the coordinating part of the system, allows for detection and recovery of possible and unpredictable concurrent activities conflicts. Moreover, the approach allows the enforcing of coordination policies on the composed system by automatically synthesizing the policy-satisfying assembly code.