Project Scope is "The work that needs to be accomplished to deliver a product, service, or result with the specified features and functions." 
Product Scope is "The features and functions that characterize a product, service, or result." 
1. A Guide to the Project Management Body of Knowledge (PMBOK Guide) - Fourth Edition. Project Management Institute, 2008. ISBN 978-1-933890-51-7
The SaS PMO has a number of scoping exercise that teams can use.