An Approach to Measure Java Code An Approach to Measure Java Code Quality in Reuse EnvironmentQuality in Reuse Environment

Aline TimóteoAline TimóteoAdvisor: Silvio MeiraAdvisor: Silvio Meira

UFPE – Federal University of PernambucoUFPE – Federal University of Pernambucoalt.timoteo@gmail.comalt.timoteo@gmail.com

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SummarySummary

Motivation Background

Metrics An Approach to Measure Java Code Quality Main Contributions Status

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MotivationMotivation

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MotivationMotivation

Reuse Benefit Productivity Cost Quality Reuse is a competitive advantage!!!!!

Reuse environment [Frakes, 1994] Process Metrics Tools

Repository Search engine Domain tools …

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ProblemProblem

Component Repository promote reuse success [Griss, 1994]

Artifacts quality must be assured by the organization that maintains a repository? [Seacord, 1999]

How to minimize low-quality artifacts reuse?

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BackgroundBackground

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MetricsMetrics

“Software metrics is a method to quantify attributes in software processes, products and projects” [Daskalantonakis, 1992]

Metrics Timeline

Age 1: before 1991, where the main focus was on metrics based on the code complexity

Age 2: after 1992, where the main focus was on metrics based on the concepts of Object Oriented (OO) systems

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Age 1: Complexity Age 2: Object Oriented

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Most Referenced MetricsMost Referenced Metrics

LOC

Cyclomatic Complexity [McCabe, 1976]

Chidamber and Kemerer Metrics [Chidamber, 1994]

Lorenz and Kidd Metrics [Lorenz, 1994]

MOOD Metrics [Brito, 1994]

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Problems related to Metrics Problems related to Metrics [Ince, 1988 and Briand, 2002][Ince, 1988 and Briand, 2002] Metrics Validation

Theoretical Validation Measurement goal Experimental hypothesis Environment or context

Empirical validation

Metrics Automation Different set of metrics implemented Bad documentation Quality attributes x Metrics

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An Approach to An Approach to Measure Java Code Measure Java Code

QualityQuality

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An Approach to Measure Java Code QualityAn Approach to Measure Java Code Quality

Quality Attributes x Metrics

Metrics Selection and Specification

Quality Attributes measurement

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Quality in a Reuse Environment Quality in a Reuse Environment [Etzkorn, 2001][Etzkorn, 2001] ISO 9126

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Quality Attributes x MetricsQuality Attributes x Metrics

 Quality Attributes  Code Attributes  LOC Cyclomatic Complexity     CK Metrics      

    WMC DIT NOC CBO RFC LCOM

  size x              

Analyzability complexity   x x x     X X

  documentation x               

  complexity   x x x     X X

 modularity/

encapsulation               X

Changeability coupling           x   X

  cohesion               X

  inheritance       x        

Stability                  

Testability complexity   x x x     X X

  coupling           x   X

  complexity   x x x     X x

  documentation x               

Reusabilitymodularity/

encapsulation               x

  coupling           X   x

  cohesion               x

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Metrics SelectionMetrics Selection

Applicable for Java

Empirical Validation

Theoretical Validation

Acceptance

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Metrics SelectionMetrics Selection

McCabe Metric [McCabe, 1976] Theoretical Validation, according to graphos teory

Independence of technology

Empirical Validation

Acceptance [Refactorit, 2001; Metrics, 2005; JHawk, 2007]

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Metrics SelectionMetrics Selection

CK Metrics [Chidamber, 1994], Theoretical Validation,

Developed in a OO context

Empirical Validation [Briand, 1994; Chidamber, 1998; Tang, 1999].

Acceptance [Refactorit, 2001; Metrics, 2005; JHawk, 2007]

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Metrics SpecificationMetrics Specification

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Quality Attributes Measurement (QAM)Quality Attributes Measurement (QAM)

QAM = (the number of metrics that have a allowable value)

Heuristically

QAM >= Number of metrics /2

Example:

2,5 <= QAM <= 5

 Quality Attribute

 Code Attribute  CK Metrics 

    WMC DIT CBO RFC LCOMTestability

 complexity x x   x x

coupling     x   x

Max Testability = 5

Min Testability = 2,5

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Approach AutomationApproach Automation

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Approach AutomationApproach Automation

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AnalyzabilityQAM = 3.0-------> RFC: 2.0-------> WMC 1.0-------> CC 0.0

ChangeabilityQAM = 3.0-------> CBO 3.0-------> RFC: 2.0-------> WMC 1.0

public class Client implements Runnable, CommandListener {

/** * Start the client thread */ public void start() { Thread t = new Thread(this); t.start(); } }

ExperimentExperiment

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ExperimentExperiment

Main Question The retrieval component quality is better?

Compare B.A.R.T. search results Results before introduce filter Results after introduce filter

Apply questionnaire for customers

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Main ContributionsMain Contributions

Introduce quality analysis in a repository

Reduce code problem propagation

Highest Reliability

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Current StageCurrent Stage

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ReferênciasReferências [Frakes, 1994] W. B. Frakes and S. Isoda, "Success Factors of Systematic Software Reuse," IEEE Software, vol. 11, pp.

14--19, 1994. [Griss, 1994] M. L. Griss, "Software Reuse Experience at Hewlett-Packard," presented at 16th International Conference

on Software Engineering (ICSE), Sorrento, Italy, 1994. [Garcia, 2006] V. C. Garcia, D. Lucrédio, F. A. Durão, E. C. R. Santos, E. S. Almeida, R. P. M. Fortes, and S. R. L. Meira,

"From Specification to Experimentation: A Software Component Search Engine Architecture," presented at The 9th International Symposium on Component-Based Software Engineering (CBSE 2006), Mälardalen University, Västerås, Sweden, 2006.

[Etzkorn, 2001] Letha H. Etzkorn, William E. Hughes Jr., Carl G. Davis: Automated reusability quality analysis of OO legacy software. Information & Software Technology 43(5): 295-308 (2001)

[Daskalantonakis, 1992] M. K. Daskalantonakis, “A Pratical View of Software Measurement and Implementation Experiences Within Motorola”, IEEE Transactions on Software Engineering, vol 18, 1992, pp. 998–1010.

[McCabe, 1976] T. J. McCabe, “A Complexity Measure”. IEEE Transactions of Software Engineering, vol SE-2, 1976, pp. 308-320.

[Chidamber, 1994] S. R. Chidamber, C. F. Kemerer, “A Metrics Suite for Object Oriented Design”, IEEE Transactions on Software Engineering, vol 20, Piscataway - USA, 1994, pp. 476-493.

[Lorenz, 1994] M. Lorenz, J. Kidd, “Object-Oriented Software Metrics: A Practical Guide”, Englewood Cliffs, New Jersey - USA, 1994.

[Brito, 1994] A. F. Brito, R. Carapuça, "Object-Oriented Software Engineering: Measuring and controlling the development process", 4th Interntional Conference on Software Quality, USA, 1994.

[Ince, 1988] D. C. Ince, M. J. Sheppard, "System design metrics: a review and perspective", Second IEE/BCS Conference, Liverpool - UK, 1988, pp. 23-27.

[Briand, 2002] L. C. Briand, S. Morasca, V. R. Basili, “An Operational Process for Goal-Driven Definition of Measures”, Software Engineering - IEEE Transactions, vol 28, 2002, pp. 1106-1125.

[Morasca, 1989] S. Morasca, L. C. Briand, V. R. Basili, E. J. Weyuker, M. V. Zelkowitz, B. Kitchenham, S. Lawrence Pfleeger, N. Fenton, "Towards a framework for software measurementvalidation", Software Engineering, IEEE Transactions, vol 23, 1995, pp. 187-189.

[Seacord, 1999] Robert C. Seacord. Software engineering component repositories. Technical report, Software Engineering Institute (SEI), 1999

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[Refactorit, 2001] Refactorit tool, online, last update: 01/2008, available: http://www.aqris.com/display/ap/RefactorIt

[Jdepend, 2005] JDepend tool, online, last update: 03/2006,available: http://www.clarkware.com/software/JDepend.html

[Metrics, 2005] Metrics Eclipse Plugin, online, last update: 07/2005, available: http://sourceforge.net/projects/metrics

[Jhawk, 2007] JHawk Eclipse Plugin, online, last update: 03/2007, available: http://www.virtualmachinery.com/jhawkprod.htm

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Aline TimóteoAline Timóteo

UFPE – Federal University of PernambucoUFPE – Federal University of Pernambuco

alt.timoteo@gmail.comalt.timoteo@gmail.com

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