Book Pick: MBSE & Reuse

Excerpt from Enterprise Architecture Fundamentals:

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Scaling up MBSE to enterprise architecture entails a separation of concerns (represented by business, Use, and system cases; cf. chapter 13) and a selective management of modeling assets (represented by descriptive, prescriptive, and technical models). In between, objectives, options, and undertakings can be detailed in terms of reuse (figure 14-13):

  • Anchors and business entities, identified in descriptive models (a), are meant to be reused all along engineering processes.
  • Aspects (attributes and operations) are first introduced by descriptive models (d), and then refactored to set apart business aspects from systems functional ones; specifically, the messages exchanged at the architecture level, defined by Use cases (e) and prescriptive models (f ), are set apart from the features (or interfaces) at the component level, defined by system cases and technical models (g).
  • Business logic is defined by descriptive models (b) and possibly refined by Use cases (c).
Figure 14-13. The Matter of Reuse

The reuse of anchors and business entities (a) is necessary because it determines the continuity and consistency of the whole of enterprise architecture. It is also straightforward because anchors can be unambiguously defined and managed by business stakeholders. Likewise for business logic: assuming it can be factored out, its reuse in business domains (b) or Use cases (c) can be unequivocally decided by business analysts (cf. chapter 12).

By contrast, the reuse of aspects is front and center for disputed architecture issues:

  • For aspects defined in descriptive models, the purpose of reuse is to set apart the intrinsic semantics of enterprise anchors (e.g., accounting) from their understanding by business domains (d).
  • For aspects defined in Use cases, the purpose is to share user interfaces across business applications (e).
  • For aspects defined in prescriptive models, the purpose is to share access to business functions; e.g., invoicing or establishing a credit rating (f ).
  • For aspects defined in system cases, the purpose is to share access to supporting functions or services; e.g., authentication or authorization (g). The reuse of models thus appears as the logical counterpart of their transformation; but reuse should also be considered in the broader context of enterprise architecture.

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(From Chapter 14)
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