It is shown how an enterprise portal, supporting a community of users discharging roles expressed as combinations of plans and constraints, can be usefully guided by a constraint processor. In particular, constraint logic programming on finite domains provides the users with useful insights regarding their possible work schedules. Constraints assist also in shaping the electronic artefacts created and transmitted by the users. The implementation is supported by mechanisms for assigning and updating roles and for assisting the search for remedies in the case of constraint failure 411