MC$C (PURCHIS: MatGrp QtyRelblty Selection) is a standard SAP transaction code available within R/3 SAP systems depending on your version and release level.
Below for your convenience is a few details about tcode MC$C including any standard documentation available. In-order to use this transaction within your SAP system simply enter it into the command input box located in the top left hand corner and press enter. Here are a few additional command options available to use when doing this.
SAP Menu->Information Systems->Logistics->Purchasing->Material Group->Quantity Reliability
SAP Menu->Information Systems->General Report Selection->Materials Management->Purchasing->Purchasing Information System->Material Pricing Group->PURCHIS: MatGrp QtyRelblty Selection
For futher details and documentation see program RMCE0300.