The buying decision process is the decision-making process used by consumers regarding market transactions before, during, and after the purchase of a good or service. It can be seen as a particular form of a cost–benefit analysis in the presence of multiple alternatives.
Common examples include shopping and deciding what to eat. Decision-making is a psychological construct. This means that although a decision can not be "seen", we can infer from observable behaviour that a decision has been made. Therefore, we conclude that a psychological "decision-making" event has occurred. It is a construction that imputes commitment to action. That is, based on observable actions, we assume that people have made a commitment to effect the action.
Nobel laureate Herbert A. Simon sees economic decision-making as a vain attempt to be rational. He claims (in 1947 and 1957) that if a complete analysis is to be done, a decision will be immensely complex. He also says that peoples' information processing ability is limited. The assumption of a perfectly rational economic actor is unrealistic. Consumers are influenced by emotional and nonrational considerations making attempts to be rational only partially successful.
The stages of the buyer decision process were first introduced by Engel, Blackwell and Kollat in (1968).
These five stages are a framework to evaluate customers' buying decision process. While many consumers pass through these stages in a fixed, linear sequence, some stages such as evaluation of alternatives may occur throughout the purchase decision. The time and effort devoted to each stage depends on a number of factors including the perceived risk and the consumer's motivations. In the case of an impulse purchase, such as the purchase of a chocolate bar as a personal treat, the consumer may spend minimal time engaged in information search and evaluation and proceed directly to the actual purchase.
Problem/Need-recognition is the first and most important step in the buying decision. Without the recognition of the need, a purchase cannot take place. The need can be triggered by internal stimuli (e.g. hunger, thirst) or external stimuli (e.g. advertising). Maslow held that needs are arranged in a hierarchy. According to Maslow's hierarchy, only when a person has fulfilled the needs at a certain stage, can he or she move to the next stage. The problem must be the products or services available. It's how the problem must be recognized.