Software Quality Model

1
Software Quality Model

• Swat4j Quality Model Overview

2
Software Metrics

• Software metrics deals with the measurement of
  software product and the process by which it is
  developed.
• Software metrics can be classified as either
  product metrics (internal metrics) or process
  metrics(external metrics). Product metrics are
  measure of the software product measured from
  artifacts of the software, while Process Metrics
  are measures of software development process,
  such as overall development time, methodology and
  staff experience etc.

3
Software Metrics

• Product (Internal) Metrics such as SEI
  Maintainability Index, Cyclomatic Complexity and
  Object Oriented Metrics helps us to understand
  software quality goals such as Testability,
  Maintainability, Design Quality,
  Understandability, Reusability ..
• One can use these metrics to understand the
  quality of code. For e.g..
• Cyclomatic Complexity can be used to understand
  the Testability of code,
• SEI Maintainability Index can be used to
  understand the Maintainability of code.

4
Software Best Practices

• Disciplined personal practices can reduce defect
  introduction rates by up to 75 percent. - Barry
  Boehm, Victor R. Basili
• Like Software Metrics, best practices rules can
  help us understand quality conformance levels of
  source code.

5
Technology

• Fortunately we have an effective technology
  Static Code Analysis to automate these
  measurements ( Software Metrics Best
  Practices).
• Static code analysis is a technique of analyzing
  software without actually executing it. It can be
  used to reverse engineer the structural and
  relational information of software from source
  code. A simple but very useful technique to
  automatically extract information about the
  software and its components.

Source Code
Static Analysis
Facts
6
Quality Model

• So, automated Software Metrics and Best
  Practices measurements enables us to reflect on
  developed codes quality.
• However, raw measurements is not enough to
  translate organizational quality vision.
• Hence, Swat4j provides a framework to express
  common quality goals in terms of software metrics
  and software best practices, and automates the
  process of evaluating the achievements.
• Swat4j is Java static code analyzer, but the
  model can be extended to other programming
  languages.

7
Predicate Contribution

• Software metrics and best practices are
  collectively called as predicates of one or
  more quality goals and one or more predicates can
  contribute to evaluate a quality goal.
• Predicate contribution can be controlled using
  weight.
• Accepted range of predicates are controlled by
  setting best/worst thresholds.

8
Example

• Lets take two predicates a.) Cyclomatic Complex
  of method (CC_MTD) b.) Percentage of comments in
  a method. (POC_MTD).
• An example of predicate contribution to goals

• Lets assume that
• CC_MTD Best Threshold 4.0 and Worst
  Threshold9.0
• (up to 4 conditions in a method is OK, beyond 9
  conditions in a method is to invite trouble)
• POC_MTD Best Threshold20 and Worst Threshold5
• (a method with 20 comment will be easy to
  understand/maintain than a method with less than
  5)
• As we can see that CC_MTD can contribute five
  quality goals and POC_MTD contributes to three
  quality goals. For instance, Maintainability
  can be quantified using POC_MTD and CC_MTD where
  POC_MTD is twice as important as CC_MTD.
• Swat4j provides about 150 predicates across five
  levels and six quality goals.

9
Configuring Quality Model

• Code quality can be very ambiguous is left
  un-defined.
• Swat4j provides a quantitative means to define a
  code quality for your project/organization and
  automates the process of evaluation.
• Since the quality model is highly customize-able
  organizations can express quality in way that
  fits for them.

10
Further

• Swat4j team keeps adding metrics and best
  practices from time to time.
• Giving you more predicates to evaluate code
  quality.
• Swat4j comes with a default quality model, which
  can be customized quickly to fit needs.
• Swat4j team are actively involved developing
  stereo types of Quality Models for different
  types of application. For e.g.. Model for UI
  intensive apps, Model for App. Servers, etc.

11
Define, Analyze Improve
Swat4j Control Code Quality
12
Usage scenarios

• Control quality of outsourced software
  maintenance.
• Control quality of product development.
• Understand softwares quality (maintainability,
  testability ..etc) before accepting software
  maintenance projects.
• As an acceptance criteria, for outsourced
  development.
• Evaluate open source products before adopting.
• In learning/training environments.

13
Demo Download

• Demo Video - Quality Model In Action or
• Visit http//www.codeswat.com
• Download a free trial version
• Try it before you choose to buy
• Talk to us at sales_at_codeswat.com