The initial identification of viewpoints that are relevant to a system can sometimes be difficult. To help with this process, you should try to identify viewpoints of different types:
- Providers of services to the system and receivers of system services.
- Systems that should interface directly with the system being specified.
- Regulations and standards that apply to the system.
- The sources of system business and non-functional requirements.
- Engineering viewpoints reflecting the requirements of people who have to develop, manage and maintain the system.
- Marketing and external affairs viewpoints that generate requirements on the product features expected by customers and how the system should reflect the external image of the organisation.