Enterprise Architecture (EA) provides a representation of the business in terms of its components and component relationships in order to facilitate business change. It mediates our knowledge and understanding of the underlying organizational system and focuses our attention to the relevant aspects thereof. Thereby, the systemic lens through which EA is conceptualized determines the leverage of change that it supports. It is of essence that EA requisitely reflects the degree of business change that it is purported to support. "The map is not the territory", but it is useful insofar it is structurally isomorphic to the territory.
In the following, I will put forth a five-scale classification of system views, discuss the leverage of change characteristic to each view, and suggest the respective requisite approach to EA. Figure 1 illustrates these conjectures.
Static SystemIn the static system view, the structural properties, the state and the throughput of the system do not display consequential change over time. The focus is on context: how the parts are related to the whole. The system can be adequately conceptualized as a closed system, i.e. as a self-contained system with no interaction with external elements.
The static system view is hardly enough to conceptualize any organization as a whole, but it has some applicability in optimizing the structure and performance of organizational subsystems under relatively steady-state conditions. EA that reflects this view serves the purpose of reducing costs and improving efficiency, mostly at the infrastructure level.
Reactive SystemIn the reactive system view, the organization exhibits dynamic stability: it seeks internal stability and retains its state in a changing environment by internal adjustments. The reaction to changes is deterministic: when perturbed, the system will seek internal equilibrium through negative feedback. As the system interacts with and is affected by its environment, the closed system view is inadequate and open system characteristics come into play.
The reactive system view is requisite in a "business as usual" setting. It is required when the situational variety calls for some degree of assessment and adaptation, but the basic means towards the ends need not be changed. EA reflects the reactive system view with its emphasis on processes, work practices and quality standards: architectural support of implementation projects, development guidelines, change management practices, etc. Reactive EA supports reliable business-IT alignment and focuses on changes in the information systems landscape.
Responsive SystemIn the responsive system view, the system is able to learn. Whereas a reaction is deterministically caused by an event, a response entails a choice of behavior. The responsive system is able to counter large displacements from equilibrium and even enter a new equilibrium domain as the resilience of its prior equilibrium domain becomes exhausted.
The responsive system view is required to address not only the tried-and-true but also the conceivable future contingencies. The view allows devising new means to achieve the goals, but not changing those goals. In the responsive system view, EA emphasizes effectiveness. The importance of inter-domain relationships is heightened. Reusable architecture building blocks enable expeditious reassembly of business processes and solution architecture practice facilitates capability improvement.
Proactive SystemIn the proactive system view, the organization initiates change and reinforces it through positive feedback rather than reacts or responds to events and dampens change through negative feedback mechanisms. The organization is autonomous with respect to setting its goals. The proactive system exhibits chaordic properties: its behavior is unpredictable yet patterned, chaotic and orderly, simultaneously.
The proactive system view is required when introducing new products or services and changing the means and ends of respective work systems within the overall business purpose. Proactive EA embraces business architecture, linking enterprise assets and capabilities with BA elements such as products, services, organizational goals, core competencies and strategic change programs.
Evolving SystemIn the evolving system view, the system and its constituents co-evolve with and co-adapt to other systems and their components at all levels of scale. The stability landscape is dynamically changing as each agentic system strives to increase its fitness function vis-à-vis other agents, and the overall behavior of the "system of systems" emerges through this self-organization.
The evolving system view is required when the organization is endogenously generating its goals and transforming itself accordingly. It is needed when the very value proposition and the respective business model of the organization, including an entire range of products and services, must be changed. EA, as per this view, must enable continuous transformative change at the SBU level and ensure sustained resilience (cf. "panarchitecture").