A-ESA

Agile Enterprise Solution Architecture

5C Area Model for Enterprise Solution Architecture (ESA), A Brief Introduction

Agile Enterprise Solution Architecture (referred to as Agile ESA or A-ESA) provides a link between Enterprise Architecture (EA) and Solution Architecture (SA), leaning toward the latter in an agile manner.

A-ESA acts as an intermediary between various enterprise-wide considerations and solution concerns, including strategic directions, business needs, data analysis, application design, and operational engineering.

For ease of recall, the A-ESA model can be simplified as a 5C or C5 model that captures the essence of the A-ESA areas. The 5Cs stand for Capability, Case (Scenario), (Solution) Context, Composite (Services), and Container (Environment). The 5C Area Model provides a holistic enterprise solution model for effective architectural thinking.This article briefly introduces the 5C model concept, an effective architectural style for its holistic consideration of key enterprise objectives and significant solution concerns.

5C Area Model

A-ESA 5C Area Model
Figure 1: A-ESA 5C Area Model

As seen in the figure above, the core part of these five areas coincidentally covers these 5Cs as core areas:

  • Capability of Enterprise Solutions – Reflecting heat map of enterprise solution capabilities and value stream mapping
  • Case Scenario – Clarifying requirement mapping with focus on non-functional characteristics
  • Context of Solution(s) – Identifying the boundaries of enterprise solutions from both information and technical exchanges
  • Composition (Composite Services) – Specifying functional services on top of application components with the right level of abstraction and domain analysis
  • Container Environment – Mapping functional services with deployment units based on service-level requirements including viability considerations.

Note that from a solution assurance perspective, validation can be a separate area. However, in A-ESA, validation is an iterative, incremental and dynamic process, so it can be part of the five areas.

Architectural Style(s) of Each C

These 5C areas roughly correspond to each of the following architectures:

Capability modeling is a core part of enterprise architecture, along with business architecture

Case scenario is closely related to information architecture, solution requirements, and business architecture considerations.

Information Architecture vs. Business Architecture
Information architecture is typically user-centric, focusing on how users interact with information. Business architecture is typically process-centric, focusing on how the organization operates and delivers value.
Regardless of the nomenclature, pay attention to what is actually being communicated in an ESA model.

Context is the scope and boundary of the solutions, as well as the overall consideration of internal solutions and external impacts. This is where the holistic thinking of solution architecture plays a major role.

Composite services are the determinants of solution flexibility (the ability to change) and maintainability. This is more of a software architecture, the most challenging part of an IT architecture. Note that ESA is more concerned with domain or composition of services, rather than components.

Container environment is part of the technology or operational architecture where the service level characteristics are demonstrated in an enterprise solution. It requires cross-consideration of both functional services and operational services. Note that container is not just Docker-like, including traditional application runtime containers, deployment units/packages, and the like.

Overall, it’s a style of enterprise solution architecture that takes into account of both the key directions of enterprise architecture and the key concerns of solution architecture.

5C As A Whole

A well modeled ESA should be 5C as a whole:

  • Cover all these critical areas
  • Well-correlated between the views and elements of these areas
  • Follow the S3 principle: simple, significant and then systematic as stated in the Agile ESA
  • Embody the basic thinking framework that includes abstracted landscape thinking, structural thinking, and decision thinking

5C Model-based Decision Making

A well-modeled ESA should reflect clear architectural styles or patterns, and key trade-off decisions on non-functional quality attributes.

  • Solution context level: requirement mapping, principles/guidelines, business constraints
  • Solution content level: validation, risk, viability, and governance

Note that trade-off balancing decisions are often only meaningful when using a holistic approach such as the 5C Area Model.

Summary

This article simply describes the 5C area as a catchy name for effective ESA modeling.

5C covers both EA and SA, both high-level software engineering and systems engineering considerations, both solution context and content, and both business and IT.

5C is simple, yet holistic. Architectural decisions based on 5C tend to incorporate all architecture needs (EA, SA, BA, etc.) and reflect the interests of all stakeholders within constraints.

Further Readings