1. List of important SAP MM (Material management transaction codes.)
Transaction codes for materials
MM01: Create material
MM02: Change material
MM03: Display material
Transaction codes for Reservations
MB21: Create Reservation
MB22: Change Reservation
MB23: Display Reservation
MB25: List of Reservations
Purchasing display transaction codes
ME53: Display purchase requisition
ME23 Display purchase order
ME43: Display RFQ
ME48: Display quotation
ME33K: Display contract
ME33L: Display scheduling agreement
ME13: Display info record
ME03: Display source list
MEQ3: Display quota arrangement
MP02: Display approved manufacturer parts list
ME62: Display vendor evaluation
MN03: Display RFQ message
MN06: Display purchase order message
MN09: Display outline purchase agreement message
MN12: Display scheduling agreement delivery schedule message
MN15: Display service entry sheet message
MN26: Display inbound delivery message
WWNC: Display messages for settlement run
MEB3: Display rebate arrangements
WWSC: Display conditions for subsequent
MEK3: Display conditions in purchasing

2. Transaction codes for processing RFQ (Request for quotation)
ME41: Create RFQ
ME42: Change RFQ
ME43: Display RFQ
ME44: Maintain RFQ supplement
ME45: Release RFQ
Transaction codes to maintain quotations
ME47: Enter quotation
ME48: Display quotation
ME49: Quotation price comparison list
Transaction codes to process a purchase requisition
ME51N: Create purchase requisition
ME52N: Change purchase requisition
ME53N: Display purchase requisition
Transaction codes to release Purchase Requisitions
ME54: Individual release for purchase requisitions
ME55: Individual release for purchase requisitions
ME5F: Release reminder for purchase requisitions
Transaction codes to process Purchase Orders
ME21N: Create purchase order
ME25: Create purchase order – vendor unknown
ME22N: Change purchase order
ME23N: Display purchase order
ME56: Assign source to purchase requisition
ME57: Assign and process purchase requisitions
ME58: Order for assigned purchase requisitions
ME59: Generate purchase orders from requisitions automatically
ME24: Maintain PO supplement
ME28: Release purchase order

3. Transaction codes to process a purchasing info record
ME11: Create purchasing info record
ME12: Change purchasing info record
ME13: Display purchasing info record
ME14: Display changes to purchasing info record
ME15: Flag purchasing info record for deletion
Transaction codes to process physical inventory documents.
MI01: Create Physical Inventory Document
MI02: Change Physical Inventory Document
MI03: Display Physical Inventory Document
MI21: Print Physical Inventory Document
MI07: Process List of Differences
MI08: Create List of Differences with Document
MI10: Create List of Differences without Document
MI20: Print List of Differences
MI11: Recount Physical Inventory Document
Transaction cods for Physical Inventory
MI01: Create Physical Inventory Document
MI02: Change Physical Inventory Document
MI03: Display Physical Inventory Document
MI21: Print Physical Inventory Document
MI07: Process List of Differences
MI08: Create List of Differences with Document
MI10: Create List of Differences without Document
MI20: Print List of Differences
MI11: Recount Physical Inventory Document
MI22: Display Physical Inventory Documents for Material.
MI23: Display Physical Inventory Data for Material.
MIDO: Display Changes.
MI24: Physical Inventory List.
MIAL: Read Physical Inventory Document Archive.
MI04: Enter Physical Inventory Count with Document
MI09: Enter Physical Inventory Count without Document
MI05: Change Physical Inventory Count
MI06: Display Physical Inventory Count

4. Transaction codes to process a purchase contract
ME31K: Create contract
ME32K: Change contract
ME33K: Display contract
ME34K: Maintain contract supplement
ME3P: Recalculate contract prices
MLRP: Periodic invoicing plans
Vendor Evaluation transaction codes
ME61: Maintain vendor evaluation
ME62: Display vendor evaluation
ME63: Re-evaluate automatic sub criteria
ME6A: Display changes to vendor evaluation
ME6F: Print evaluation sheet
ME6G: Vendor evaluation in the background
Transaction codes for Scheduling Agreements
ME31L: Create scheduling agreement
ME37: Create stock transport scheduling agreement
ME32L: Change scheduling agreement
ME33L: Display scheduling agreement
ME34L: Maintain scheduling agreement supplement
ME3R: Recalculate scheduling agreement prices
ME85: Re-number schedule lines
ME86: Aggregate schedule lines
ME87: Aggregate PO history
ME88: Reset agreed cumulative quantity and reconciliation date