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

• Architecture reference materials (see Part IV, 36.2.5 Architecture Repository)

9.3.2 Non-Architectural Inputs

• Request for Architecture Work (see Part IV, 36.2.17 Request for Architecture Work)
• Capability Assessment (see Part IV, 36.2.10 Capability Assessment)
• Communications Plan (see Part IV, 36.2.12 Communications Plan)

9.3.3 Architectural Inputs

• Organizational Model for Enterprise Architecture (see Part IV, 36.2.16 Organizational Model for Enterprise Architecture), including:
  • Scope of organizations impacted
  • Maturity assessment, gaps, and resolution approach
  • Roles and responsibilities for architecture team(s)
  • Constraints on architecture work
  • Budget requirements
  • Governance and support strategy
• Tailored Architecture Framework (see Part IV, 36.2.21 Tailored Architecture Framework), including:
  • Tailored architecture method
  • Tailored architecture content (deliverables and artifacts)
  • Configured and deployed tools
• Application principles (see Part III, 23.6.3 Application Principles), if existing
• Data principles (see Part III, 23.6.2 Data Principles), if existing
• Statement of Architecture Work (see Part IV, 36.2.20 Statement of Architecture Work)
• Architecture Vision (see Part IV, 36.2.8 Architecture Vision)
• Architecture Repository (see Part IV, 36.2.5 Architecture Repository), including:
  • Re-usable building blocks
  • Organization-specific reference models
  • Organization standards
• Draft Architecture Definition Document (see Part IV, 36.2.3 Architecture Definition Document), including:
  • Baseline Business Architecture, Version 1.0 (detailed), if appropriate
  • Target Business Architecture, Version 1.0 (detailed)
  • Baseline Data Architecture, Version 0.1
  • Target Data Architecture, Version 0.1
  • Baseline Application Architecture, Version 0.1
  • Target Application Architecture, Version 0.1
• Draft Architecture Requirements Specification (see Part IV, 36.2.6 Architecture Requirements Specification), including:
  • Gap analysis results (from Business Architecture)
  • Relevant technical requirements that will apply to Phase C
• Business Architecture components of an Architecture Roadmap (see Part IV, 36.2.7 Architecture Roadmap)

9.4 Steps

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

• 10. Phase C: Information Systems Architectures - Data Architecture
• 11. Phase C: Information Systems Architectures - Application Architecture

9.5 Outputs

The main outputs of Phase C are:

• Refined and updated versions of the Architecture Vision phase deliverables, where applicable, including:
  • Statement of Architecture Work (see Part IV, 36.2.20 Statement of Architecture Work), updated if necessary
• 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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Downloads of TOGAF®, an Open Group Standard, are available under license from the TOGAF information web site. The license is free to any organization wishing to use the TOGAF standard entirely for internal purposes (for example, to develop an information system architecture for use within that organization). A book is also available (in hardcopy and pdf) from The Open Group Bookstore as document G116.