© 2009, Cognizant Technology Solutions. All Rights Reserved. The information contained herein is subject to change without notice.

Software Architecture & Quality

Topics

2© 2009, Cognizant Technology Solutions. Confidential

Architects’ Quality Footprints in an Enterprise

Quality from an Architectural Perspective

Measuring Architecture & Design Quality

Quality from an Architectural Perspective

3© 2009, Cognizant Technology Solutions. Confidential

• “Information Processing/data automation implications of Air Force command and control requirements in the 1980’s”, U.S. Air Force, SAMSO/XRS-71-1, April 1972

• “Characteristics of software quality”, TRW Document No. 25201-60001-RU-OO, December 28, 1973

• J. McGonagle, A study of a Software Development Project, J.D. Anderson & Associates, October, 1971

Software Quality

Maintainability

Extensibility

Performance

Scalability

Portability

Reliability

Interoperability

…

• Errors Found After Acceptance Test• Coding Defects: 10%• Design Defects: 45%

• Later a “defect” is fixed more is the cost though code defects are cheaper to fix than design defects

• “More” time spent in design reduces cost

Measuring Architecture & Design Quality

4© 2009, Cognizant Technology Solutions. Confidential

Reference: Applying and Interpreting Object Oriented Metrics by Dr. Linda H. Rosenberg, Larry Hyatt

• WMC calculates the structural complexity on a class level.

• RFC (Response for Classes) captures the size of the response set of a class. The response set of a class consists of all the methods called by local methods.

• LCOM CK () Chidamber and Kemerer define LCOM as a count of the number of method pairs whose similarity is zero minus the count of method pairs whose similarity is not zero.

Measuring Architecture is not easy but the work is on!

Architects’ Quality Footprints in an Enterprise

5© 2009, Cognizant Technology Solutions. Confidential

Architecture Definition

Strategy & Technology Directions, Planning

Requirements

Technology Governance

Design, Coding, Testing

• Proactive over Reactive• Tangibles Driven

Communications• Validate – Measure – Test• Adopt, Learn & Educate• Review & Cross Check• Tools & Templates Driven• Reuse of Building Blocks• Principles, Standards,

Guidelines, Models Driven

© 2009, Cognizant Technology Solutions. Confidential 6

Thank you