The Engel-Kollat-Blackwell model consist of four components:

i. Information processing: this component comprises the consumer’s selective exposure, attention, comprehension and retention of stimuli relating to a product or brand received from marketing and non-marketing sources. As a marketer, the first step is to ensure that a consumer is exposed to your message or stimuli, pays attention to it, understands what it is all about and also remembers it.

ii. Central Control Unit: The stimuli thus received and retained are processed in the central control unit. The stimuli is processed and interpreted with the help of four psychological filter:

• Stored information and past experience about the product/brand which serves as a memory for comparing different alternatives;
• Evaluative criteria which the consumer uses in judging the alternatives;
• General and specific attitudes which influence the purchase decision;
• Basic personality traits, which influence how the consumer is likely to respond to various alternatives.

iii. Decision process: The decision process component of the model consist of:

• Problem recognition
• Internal search and evaluation
• External search and evaluation
• Purchase processes
• Decision outcomes

If the purchase decision is such that it requires extensive problem solving, the consumer would go through all the above five stages. In case of limited problem solving or routinised response behaviour, some of the intervening stages may be skipped and the consumer may directly reach the purchase decision.

iv. Environmental Influences: The environmental factors that may influence the consumer’s purchase decision are income, culture, family, social class and physical situations. Depending on the specific product under consideration, these factors may have a favorable or unfavorable influence on the purchase decision.