Unilateral: is essentially a purchase order for standardized routine items. Vendors often accept the orders automatically without even signing them in advance
- Bilateral: can be initiated one of three ways
- - IFB - Appropriate for routine items where the buyer's objective is simply to get the best possible price
- RFQ - used for purchase of low monetary value commodity items.
- RFP - used for complex, non-standard items of relatively high monetary value