In an organization, purchasing decisions involve several roles that contribute to selecting and acquiring products or services. Understanding the dynamics of these roles can shed light on how decisions are made and who influences these choices.

Users are the members who will directly interact with the product or service. Their input is essential in identifying specific needs and helping to define technical and functional specifications. For instance, in a manufacturing company, the production team might recognize the necessity for a new machine, specifying performance criteria and operational features to ensure compatibility with existing processes.

Influencers provide critical input and technical expertise during the evaluation of potential solutions. These individuals or departments, such as engineering, offer insights into the technical requirements, alternative suppliers, and product performance. Based on their domain knowledge, they hold substantial sway in shaping the final specifications, making their contributions indispensable to the decision-making process.

Buyers have the formal responsibility to select suppliers and manage the purchasing process. While they may contribute to developing specifications, their primary role is vendor selection and contract negotiation. In large-scale or complex purchases, such as acquiring enterprise software, high-ranking officers, such as the Chief Financial Officer (CFO), might be involved to ensure the deal aligns with the organization's financial goals and strategies.

Deciders hold the authority to make the final choice of suppliers. In simpler transactions, such as routine office supplies purchases, the roles of buyers and deciders may overlap. However, deciders can be distinct from buyers in more significant decisions, possessing the formal or informal power to approve the final decision.

Gatekeepers regulate the flow of information within the organization, controlling access to users, influencers, and deciders. These individuals, such as purchasing agents or secretaries, often manage interactions between external vendors and key decision-makers, ensuring only relevant information reaches the appropriate people.