System functions, requirements, project and portfolio management

System functions (capabilities) represent the link between the relevant department or business process and IT or the IT system. It is therefore not only possible to document which IT system supports the process, but also how it is done, that is, which system function of the IT system is used for process execution. This is illustrated in the following figure:

The system functions are managed in a separate model of the Service architecture diagram type and can be divided into technical domains if required. This guarantees a uniform description of IT systems with regard to their functionality. As a result, system redundancies can be identified, alternative IT systems found, and optimum support provided for migration projects.

However, system functions can also be derived from a business process and thus represent technical IT requirements. If none of the available IT systems support a system function derived from the processes, the function can be linked with a requirement:

All functional and non-functional requirements are structured and managed in requirements trees.

In contrast to system functions (capabilities), requirements are temporary in nature. After successful implementation of a requirement, the functionality is available in accordance with the system function requirement.

The project required for implementation can also be represented in ARIS. Projects can be structured using project tasks. Individual project tasks can be described, for example, in terms of objectives to be achieved, affected organizational units, persons in charge, and affected IT systems.

Individual cells in a process support map can also be linked to a task. This indicates that a specific cell or process support unit will be processed in the course of a project, for example, as part of a migration scenario.

Individual tasks can then be combined in programs.

A project schedule is used to represent the chronological dependency of the relevant tasks. Arranging tasks on a timeline and illustrating existing dependencies result in a detailed project schedule as shown in the figure below.