The buyer type model comes from marketing. In this model there are four different roles people may play in the purchasing process.

Buyer -The person who pays the bill.
User – The person who uses the product.
Influencer – The person who influences the decision to buy.
Decider – The person who makes the decision to purchase the product.

For some products the buyer, user and decider are the same person. However, if these roles are played by different people then representatives of each group should be interviewed during the product design process to ensure that the design of the product reflects their needs, desires and expectations.

Example Wheel Chair Restraints for Public Buses

Buyer – The bus manufacturers purchase the interior seats and wheel chair restraints.
User – Bus riders who use mobility devices and the bus drivers.
Influencer(s) – Bus Maintenance personnel, advocate groups for the disabled.
Decider – The transportation authorities who purchase the complete buses and operate the buses decide which seats and wheel chair restraint systems will be installed.

Why is it important to identify all of the people who play a role in the buying process?