A.1. Determination of requirements
2. Vendor selection
3. Purchase order handling
4. Goods receipt
5. Invoice verification

B.1. Source of supply determination
2. Vendor selection
3. Determination of requirements
4. Purchase order handling
5. Goods receipt

C.1. Vendor selection
2. Source of supply determination
3. Purchase order monitoring
4. Goods receipt
5. Handling of payments

D.1. Determination of requirements
2. Purchase order handling
3. Handling of payments
4. Goods receipt
5. Invoice verification