MD01 re-planning does not seem to work in SAP

The Issue

I have run MD01 for a specific scope of planning and it has planned the materials sucessfully. The problem is that if I try to re-run MD01 again (planning mode = 3), it doesn't plan any material. How should I solve this problem?

The Solution

Planning mode is not the solution.
You need to change the Processing Key from NETCH to NEUPL.
If you leave it at NETCH, this means that, whatever that have been planned before & changes were made, it will still not regenerate the MRP planning.
So to Re-plan, you need to use NEUPL.

So your settings should be
NEUPL
3 Planned Orders (If you want PRs then change it to 1)
3 Schedule Lines
1 MRP List
3 Delete and recreate planning Data

Source: http://forums.sdn.sap.com/thread.jspa?threadID=1667016&messageID=9011964#9011964