The development of complex systems involves multiple participants (stakeholders) who have their own perspectives, knowledge, experience, and responsibilities that determine their requirements to the system. It is important to coordinate stakeholders and unify their requirements. We propose a method that takes into account the perspectives of all stakeholders. The framework for defining of system’s problem area defines the boundaries within which the system is developed. The reference methodology for system development is based on the IEEE 1471 and 42010 standards. We use a few viewpoints: Information Security, Risk Analysis, Communication, Technological, and Information Processing. The analysis of the different perspectives allows us to construct models describing the features of the developed system. After analyzing the Information Security viewpoint, a generalized conceptual model of the system is created. The analysis of Information Processing leads to a data model. Technological point of view includes different technological approaches for the development of systems, such as object-oriented approach with UML Language for constructing the design model and agent-based modeling approach for creating a simulation model of the system. We present how the object-oriented design model described with UML can be transformed into an agent-based simulation model.