Simple Architectures for Complex Enterprises

Simple Architectures for Complex Enterprises

by Roger Sessions
Released May 2008
Publisher(s): Microsoft Press
ISBN: 9780735625785

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Book description

Dismantle the overwhelming complexity in your IT projects with strategies and real-world examples from a leading expert on enterprise architecture. This guide describes best practices for creating an efficient IT organization that consistently delivers on time, on budget, and in line with business needs.

IT systems have become too complex—and too expensive. Complexity can create delays, cost overruns, and outcomes that do not meet business requirements. The resulting losses can impact your entire company. This guide demonstrates that, contrary to popular belief, complex problems demand simple solutions. The author believes that 50 percent of the complexity of a typical IT project can and should be eliminated—and he shows you how to do it.

You’ll learn a model for understanding complexity, the three tenets of complexity control, and how to apply specific techniques such as checking architectures for validity. Find out how the author’s methodology could have saved a real-world IT project that went off track, and ways to implement his solutions in a variety of situations.

Table of contents

  1. Dedication
  2. Acknowledgments
    1. Legal Notices
  3. Introduction
    1. The Organization of This Book
    2. Find Additional Content Online
    3. Support for This Book
      1. Questions and Comments
  4. I. The Question of Complexity
    1. 1. Enterprise Architecture Today
      1. Why Bother?
        1. Issue: Unreliable Enterprise Information
        2. Issue: Untimely Enterprise Information
        3. Issue: New Complex Projects Underway
        4. Issue: New Companies Being Acquired
        5. Issue: Enterprise Wants to Spin Off Unit
        6. Issue: Need to Identify Outsourcing Opportunities
        7. Issue: Regulatory Requirements
        8. Issue: Need to Automate Relationships with External Partners
        9. Issue: Need to Automate Relationships with Customers
        10. Issue: Poor Relationship Between IT and Business Units
        11. Issue: Poor Interoperability of IT Systems
        12. Issue: IT Systems Unmanageable
        13. The Value of Enterprise Architecture
      2. Common Definitions
      3. What Is Enterprise Architecture?
      4. Complexity in Enterprise Architectures
      5. The Zachman Framework for Enterprise Architectures
      6. The Open Group Architecture Framework
      7. Federal Enterprise Architecture
      8. Summary
    2. 2. A First Look at Complexity
      1. Partitioning
        1. Executive Lunch
        2. Choir Rehearsal
        3. Emergency Responses
        4. Clothing Store
        5. Chess Games
        6. Children at Starbucks
        7. Rubik’s Cube
      2. Five Laws of Partitions
        1. First Law: Partitions Must Be True Partitions
        2. Second Law: Partition Definitions Must Be Appropriate
        3. Third Law: Partition Subset Numbers Must Be Appropriate
        4. Fourth Law: Partition Subset Sizes Must Be Roughly Equal
        5. Fifth Law: Subset Interactions Must Be Minimal and Well Defined
      3. Simplification
      4. Iteration
      5. Summary
    3. 3. Mathematics of Complexity
      1. Looking at Complexity
      2. Laws of Complexity
      3. Homomorphisms
      4. Controlling Complexity in Dice Systems
      5. Adding Buckets
      6. Partitioning
      7. Equivalence Relations
      8. Equivalence Classes
      9. Inverse Equivalence Relations
      10. Equivalence Relations and Enterprise Architectures
      11. Synergistic in Practice
      12. Removing Faces
      13. Removing Buckets
      14. Other Measures of Complexity
      15. Complexity in Theory and in Practice
      16. Summary
  5. II. The Quest for Simplification
    1. 4. The ABCs of Enterprise Partitions
      1. Review of the Mathematics
      2. Partitioning the Enterprise
      3. The ABCs of Enterprise Equivalence Classes
      4. ABC-Type Relationships
      5. Implementations and Deployments
      6. ABC Types
      7. Type Hierarchies
      8. Composition Relationships
      9. Partner Relationships
      10. Relationships and Partition Simplification
      11. Retail Operation, Again
      12. Summary
    2. 5. SIP Process
      1. Overview
      2. Phase 0: Enterprise Architecture Evaluation
        1. Issue: Unreliable Enterprise Information
        2. Issue: Untimely Enterprise Information
        3. Issue: New Complex Projects Underway
        4. Issue: New Companies Being Acquired
        5. Issue: Enterprise Wants to Spin Off Unit
        6. Issue: Need to Identify Outsourcing Opportunities
        7. Issue: Regulatory Requirements
        8. Issue: Need to Automate Relationships with External Partners
        9. Issue: Need to Automate Relationships with Customers
        10. Issue: Poor Relationship Between IT and Business Units
        11. Issue: Poor Interoperability of IT Systems
        12. Issue: IT Systems Unmanageable
      3. Contraindications
      4. Phase 1: SIP Preparation
        1. Audit of Organizational Readiness
        2. Training
        3. Governance Model
        4. SIP Blend
        5. Enterprise-Specific Tools
      5. Phase 2: Partitioning
      6. Phase 3: Partition Simplification
      7. Phase 4: ABC Prioritization
      8. Phase 5: ABC Iteration
      9. Summary
    3. 6. A Case Study in Complexity
      1. Overview of NPfIT
      2. Current Status of NPfIT
      3. The SIP Approach
      4. Summary
    4. 7. Guarding the Boundaries: Software Fortresses
      1. Technical Partitions
      2. Rule 1: Autonomy
      3. Rule 2: Explicit Boundaries
      4. Rule 3: Partitioning of Functionality
      5. Rule 4: Dependencies Defined by Policy
      6. Rule 5: Asynchronicity
      7. Rule 6: Partitioning of Data
      8. Rule 7: No Cross-Fortress Transactions
      9. Rule 8: Single-Point Security
      10. Rule 9: Inside Trust
      11. Rule 10: Keep It Simple
      12. Summary
    5. 8. The Path Forward
      1. Complexity: The Real Enemy
      2. Simplicity Pays
      3. A Philosophy of Simplicity
      4. A Review of the Book Content
      5. A Parting Message
    6. A. This Book at a Glance
      1. Mathematical Concepts
        1. Mathematical Definition of a Partition
        2. Five Laws of Partitions
        3. Measuring States in a System of Dice-Like Systems
        4. Homomorphism
        5. Equivalence Relations
        6. Inverse Equivalence Relations
        7. Partitions
        8. Partitioning Algorithm for Equivalence Relations
      2. Enterprise Architectural Concepts
        1. Preferred Definition of Enterprise Architecture
        2. Definition of Optimal Architecture
        3. Boyd’s Law of Iteration
        4. Laws of Enterprise Complexity
        5. Synergistic and Autonomous
      3. SIP Concepts
        1. Definition of SIP
        2. The SIP Process
        3. ABC
        4. Software Fortress Model
        5. Three Styles of ABC Communications
        6. The SIP Mantra
  6. B. Author Biography
  7. Index
  8. About the Author
  9. Copyright

Product information

  • Title: Simple Architectures for Complex Enterprises
  • Author(s): Roger Sessions
  • Release date: May 2008
  • Publisher(s): Microsoft Press
  • ISBN: 9780735625785