Phase C: Information Systems Architectures

Chapter 9                                                                   <<< Previous | Next >>>

9.1 Objectives | 9.2 Approach | 9.3 Inputs | 9.4 Steps | 9.5 Outputs

This chapter describes the Information Systems Architectures for an architecture project, including the development of Data and Application Architectures.

Requirements Management Phase H Phase G Phase F Phase E Phase D Phase C Phase B Phase A Preliminary Phase

Figure 9-1: Phase C: Information Systems Architectures

9.1 Objectives

The objectives of Phase C are to:

  • Develop the Target Information Systems (Data and Application) Architecture, describing how the enterprise’s Information Systems Architecture will enable the Business Architecture and the Architecture Vision, in a way that addresses the Request for Architecture Work and stakeholder concerns
  • Identify candidate Architecture Roadmap components based upon gaps between the Baseline and Target Information Systems (Data and Application) Architectures

9.2 Approach

Phase C involves some combination of Data and Application Architecture, in either order. Advocates exist for both sequences. For example, Steven Spewak’s Enterprise Architecture Planning (EAP) recommends a data-driven approach.

On the other hand, major applications systems – such as those for Enterprise Resource Planning (ERP), Customer Relationship Management (CRM), etc. – often provide a combination of technology infrastructure and business application logic, and some organizations take an application-driven approach, whereby they recognize certain key applications as forming the core underpinning of the mission-critical business processes, and take the implementation and integration of those core applications as the primary focus of architecture effort (the integration issues often constituting a major challenge).

9.3 Inputs

This section defines the inputs to Phase C.

9.3.1 Reference Materials External to the Enterprise

9.3.2 Non-Architectural Inputs

9.3.3 Architectural Inputs

9.4 Steps

Detailed steps for Phase C are given separately for each architecture domain:

9.5 Outputs

The main outputs of Phase C are:

  • Refined and updated versions of the Architecture Vision phase deliverables, where applicable, including:
  • Draft Architecture Definition Document (see Part IV, 36.2.3 Architecture Definition Document), including:
    • Baseline Data Architecture, Version 1.0
    • Target Data Architecture, Version 1.0
    • Baseline Application Architecture, Version 1.0
    • Target Application Architecture, Version 1.0
    • Data Architecture views corresponding to the selected viewpoints addressing key stakeholder concerns
    • Application Architecture views corresponding to the selected viewpoints addressing key stakeholder concerns
  • Draft Architecture Requirements Specification (see Part IV, 36.2.6 Architecture Requirements Specification), including such Information Systems Architecture requirements as:
    • Gap analysis results
    • Relevant technical requirements that will apply to this evolution of the architecture development cycle
    • Constraints on the Technology Architecture about to be designed
    • Updated business requirements, if appropriate
  • Information systems components of an Architecture Roadmap (see Part IV, 36.2.7 Architecture Roadmap)

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