This is the Most commonly faced/reported issue during MRP run
Issue Reported
During the MRP run, System not creating any Procurement proposals and getting the message “No procurement proposals changed” even though there is a clear requirement.
More details of the issue:
Current requirements are reflecting in MD04 Screen (PIRs of quantities 1000,2000,3000). for the Material : FERT4, in the Plant 1710

Now if we run the MRP through MD02 transaction we can observe that

Analysis Done:
Based on the quick analysis for this reported issue, Checked the Results of the last MRP run, using MD05 transaction (MRP list).

Root Cause of the Issue
From this we can understand the issue with the exceeding maximum number of proposals that can be created. this happens when the number of procurement proposals are more than the Maximum number of order proposals that were maintained in the Configuration (T Code: OPPQ: Plant Parameters >> Error Handling)
Solution Proposed:To resolve this issue, there are two possible solutions
1. By Change/ increasing the Lot size, so that no. of proposals should not exceed 50, as per the curent config. setting
2. Increase the Max. No of Proposal limit to more than 50, at the config.

If we have constraints in changing lot sizing procedures or increasing lot size then we can change the maximum number of proposals in configuration by using OPPQ transaction

In the Error Handling option, we can increase the maximum number of proposals to the required number.
In this case, we changed the Lot Size, from 10 to 100 & Executed the MRP again

MRP Run executed successfully

Conclusion: Issue got resolved, by increasing the Lot Size, to avoid the maximum no. of proposals limit set at the configuration
Shae your valuable feedback/comments, if any
Thanks & Regards : Raja Sekhara Reddy Bannuru