I believe I understand how Work, Duration and Units interact with each other. I'm having an odd problem, though. For my task, I've selected Fixed Work (8 hours). Project (2003) then correctly calculates 1d? for Duration. When I add a resource at 40%, Project also correctly calculates 2.5?d for Duration. However, when I remove that resource, the Duration remains the same and only changes again if I assign a different resource. Is there a setting to force the Duration to recalculate upon deletion of an assigned resource?