Folgesystem

Folgesystem is a term used in systems theory and related disciplines to refer to a secondary or dependent system that emerges after, and in response to, a primary system. The folgesystem is not merely a byproduct; it includes components, processes, and interactions that rely on outputs, structures, or decisions from the primary system and may evolve alongside or after it.

The word is derived from German Folge, meaning sequence or consequence, combined with System. In practice, folgesystems appear across fields such as engineering, information technology, organizational studies, ecology, and urban planning. They describe how subsequent layers, subsystems, or networks attach to and interact with an existing core system.

Key characteristics include temporal sequencing (the folgesystem develops after the primary), dependency on the primary's outputs (data, standards, interfaces), and often a different governance or optimization objective. Coupling between the systems can be tight or loose, and the folgesystem may introduce new risks and opportunities, such as expanded functionality or added complexity.

Examples: In IT, the folgesystem encompasses downstream applications, data pipelines, and integrations that rely on a core enterprise system. In transportation planning, a folgesystem can be the ancillary services, maintenance organizations, and user support networks that arise after the main transit network is implemented.

Assessment of a folgesystem typically considers compatibility, security, and resilience with the primary system, as well as how changes in the primary system propagate to the folgesystem.

See also: subsystem, downstream system, legacy system, successor system.