Simple and elegant, the MoSCoW approach fundamentally prioritizes a project’s goals. For larger projects, I generally recommend a project MoSCoW and then a MoSCoW for each iteration of the Unified Process.
How to MoSCoW
First have the client dictate their “wish list” of items. Working together, and looking closely at their budget and timeline, you simply classify the items by Must, Should, Could and Won’t. Having the client dictate priority and recording that priority, the development team then knows where to place resources.
Requirements that must be satisfied in the final solution for the solution to be considered a success.
High priority items that shoudl be included in the solution, if possible. These are often critical requirements but ones which can be satisfied in other ways if strictly necessary.
Requirements which are considered desirable but not necessary. These will be included if time and resources permit.
Requirements that stakeholders have agreed will not be implemented in a given release, but may be considered for the future.