Nowadays increasing customer demands and competition have caused new relations to business with its micro environment especially with its suppliers. Businesses have to develop competition strategies including quality, cost and performance factors in global business world. Being aware of these factors, purchasing management is one of the most important subject for businesses. The reason for this is that purchasing management needs to be closely related with both customers and suppliers and it also needs to being able to manage quality, cost and time factors. Besides, the subject of “supplier life cycle” and “criteria for supplier selection”, assessed in purchasing management, and efficient management of these are the main factors of purchasing management. Supplying raw materials, transforming it in to finished products and distribution include so many activities related with each other and it also includes management of all these. This paper presents the theoretical perspective of the main subjects, mentioned above, and studies related concepts.