It is a typical challenge in project management of a software development project or in the selection of software to take all wishes/idea/requirements of the (future) users into account. However, a prioritization is required at some point. Criteria such as the relationship between development effort and benefit (time savings, competitive advantages) are helpful. A more basic prioritization is a classification as per the following: Must have, Should have, Could have and Won't have. In short: MuSCow.