Understanding the Concept of “Function” in TOGAF and ArchiMate

Introduction

Enterprise Architecture (EA) treats an enterprise as a system. The following tables distinguish between structure and behavior, abstract and concrete structures, and map these concepts to business architecture methods such as BIZBOK® and TOGAF®.

What TOGAF Means by “Function”

A function is a logical business component—a unit of business capability that requires physical organizational resources. Examples include core banking functions such as marketing, sales, branch management, card payment, and HR. Functions are typically arranged in a hierarchical logical organization chart.

Function vs. Capability in TOGAF

TOGAF treats functions and capabilities as synonymous. A function is described as a bounded business unit supported by clearly defined business services and implemented by business processes. Each function is constrained by the services it provides and may request services from other functions.

Interpretations of “Function” in Other Sources

Various frameworks define “function” similarly: structured analysis views it as an abstract activity element; IT4IT calls it a “functional component”; ArchiMate 3.0 mistakenly describes it as a behavior element; DoDAF and VDML use “capability” instead of “function”. Ackoff describes it as an ideal, goal, or purpose together with the behavior to achieve it. UML 2.4.1 treats a function as a basic stimulus‑response process.

ArchiMate’s Definition of “Function”

ArchiMate defines three application‑layer elements called “function” and a fourth called “application function” (behaviour). In the external view, an Application Service is an externally visible unit of functionality that exposes component functionality. In the internal view, Application Functions describe internal behaviour, while Application Components are self‑contained units of functionality.

Conclusion

Business functions are abstract activity‑structure elements extracted from real organizational units; when defined by the services they provide, they can be seen as interface definitions. A capability generally means function + goal + the people and resources needed to realize the function, i.e., a business system.