Allocating a single resource with multiple subprojects It appears that a resource with the same name in the master and in an external subproject are considered two (2) separate resources. If Sue has a task on ProjectA and Sue has a task on ProjectB and both are shown to be done on the same date, Project does not seem to recognize that the one person resource Sue cannot work on both tasks in a single day. How can I get Project to recognize that Sue is allocated on the same day as Sue from the subproject?

Are you using a resource pool? (I.e. a separate .mpp file holding all the resources, which are then shared with the various project schedules.) If not, then the resources in different projects, including master and subs, are considered unique for each project. The resource name has nothing to do with it.