Buyer behavior is the acts and the process carried out by the customers who are buying and using the product.
According to the consumerfactor.com (2015) Engel, Blackwell and Kollat in 1968, has developed a 5 stage model which explains the stages a customer goes through when purchasing a product.
The Five stages are listed below:
1. The need Recognition / Problem Recognition
2. Information search
3. Alternative evaluation
4. Purchase decision
5. Post- Purchase behavior

1. The Need Recognition / Problem Recognition
This is the first and the most important stage in the buying process, because if there is no need then there will be no purchase. The customer recognizes when there is a lag between the actual situation and ideal situation and the desired situation.
However, there are situations where not all the needs end up ass buyer behavior. For a buyer behavior to happen it requires the lag between the situations to be important. For a buyer behavior to happen recognizing the need the product price, ease of acquisition, quality …etc… should be acceptable by the customer by the level of importance the customer gives to the need.
For example:
A man needs to eat lunch every day at office, and has two options weather to get lunch delivered from pizza hut or to buy lunch from a shop few buildings away from the office place. He prefers to order and get delivered because walking away from the office might cause him to delay his works. (Ideal situation). They way to reach is ideal situation is by ordering food from pizza hut everyday which they would deliver and the total bill amount for the lunch would cost LKR 600 everyday. If he bought lunch from elsewhere it would cost less than that. The amount cannot be accepted by the customer as it seems to be high when it adds up to the whole month. So in this kind of a situation there won’t be a buyer behavior