* User – a person who uses the service. For example, if the system is developed for the accounting department, then the accountants will be the users, although the customer can be the head of this department. Often they will test the product being developed and evaluate it;

* Customer – make demands and is responsible for the result from its consumption. For example, if the system is being developed for an internal department, then the head of the department orders this system for his employees in the expectation that their work will become more efficient;

* The sponsor is the resource owner who approves the payment. For our example, it may be a CFO who considered it economically justified to develop this system to increase efficiency for such a volume with such risks in the current situation;

* Contractor – an interested party responsible for the provision of services. The contractor can be both internal and external. For architecture, they can be a development team, system engineers, individual departments integrating with their various services, and others;