When it come to marking and grades there are no real good or bad ideas just good and bad implementation (supported or hamstrung by policy).
http://www.insidehighered.com/news/2009/08/03/grading
The basic idea in the above article is, if you complete all the work you get a credit. If complete most of the work you pass. If you don’t complete enough work you fail. Students review each others work and decide if each completed item is good enough. The teacher provides the work and the marking framework for the students.
If this is treated as a way to increase teaching and learning time by reducing part of the marking load then it could be a winner. Done right, the process will produce valuable teaching opportunities.
If (as is more likely) it’s treated primarily as a way to reduce marking workload with no serious QA and no trade-off back into teaching, then it’s a potential disaster.