Uma abordagem efetiva para melhoria contínua da qualidade de software

Roberto Pepato Mellado @rpepato

Gabriel Moreira @gspmoreira

James Q. Wilson

George L. Kelling

Maintainability

Analisability

Modificability

Stability

Testability

[ISO 9126 / 25000]

Software Maintainability Maintenance Effort and

Accuracy

Preventive

why?

[Kemerer et. Al, 1999]

[Jones, 2007]

[Bennet, 2002]

Not me!

Programmers are constantly in

maintenance mode “You are rarely writing original

code.” "I'm maintaining from day one." “It's only the first 10 minutes that the code's original, when you type it in the first time. That's it.”

Don’t Make This Common Mistake

Technical Debt

Quality or Fast Delivery?

It’s not my fault, but it is still my problem

Dreaming and Planning Software Quality for his next project

Dijkstra

is Watching

[design by Philip Calçado]

Formal Inspection

Lightweight Inspection

Next, please!

Static Code Analysis

What about tools?

http://en.wikipedia.org/wiki/List_of_tools_for_static_code_analysis

FxCop (.NET)

StyleCop (.NET)

Resharper (.NET)

NDepend (.NET)

JDepend (Java)

Find Bugs (Java)

CCFinder (C#, Java, C++, VB)

SimpleCov (Ruby)

SimpleCov (Ruby)

Metric-fu -- Churn (Ruby)

Metric-fu -- Flog(Ruby)

Metric-fu -- Reek(Ruby)

Metric-fu -- Stats(Ruby)

Metric-fu -- Hotspots(Ruby)

Continuous

Inspection

CI + SCA

Metrics

Bad Smells

Inspection

Refactoring

Continuous Improvement

Measure: Cyclomatic complexity Tools • JavaNCSS • PMD • NDepend Refactorings • Replace Conditional with

Polymorphism • Extract Method

Conditional Complexity

Duplicated Code

Measure: Code duplication Tools: CheckStyle, PMD Refactorings: • Extract Method • Pull Up Method • Form Template Method • Substitute Algorithm

Measure: Source lines of code (SLOC) Tool: PMD, JavaNCSS, CheckStyle Refactorings: Extract Method, Replace Temp with Query, Introduce Parameter Object, Preserve Whole Object, Replace Method with Method Object

Long Method / Class

Measure: Efferent coupling (fan-out per class) Tool: CheckStyle, NDepend Refactorings: • Move Method • Extract Class

Excessive Dependency

Inspection Automation in CI

<target name="inspect" >

<exec program="${tools.fxcop}"

commandline="/p:${reports.scripts}\Mineradores.fxcop /out:${reports.output}\ccnet-fxcop-results.xml" failonerror="false"/>

<exec program="${tools.stylecopcmd}"

commandline="-sf &quot;${libandunittest.buildfile.path}\LibAndUnitTest.sln&quot; -of &quot;${reports.output}\ccnet-libstylecop-output.xml&quot;" failonerror="false"/>

<exec program="${tools.ndepend}" failonerror="false">

<arg value="${reports.scripts}\Mineradores-NDepend.xml" />

<arg value="/OutDir &quot;${reports.ndepend.output}&quot;" />

</exec>

</target>

NDepend Report

NDepend Report

Combination from measures of attributes belonging to a software product, or to its development process, which shows quantitatively some of its characteristics.

Métricas de Produto OO

Tamanho

•LOC

•N. Métodos

•N. Atributos

Complexidade

•CC - Complexidade Ciclomática

•Métricas de Halstead

•MCD - Max Conditional Depth

•MLD - Max Loop Depth

•DD - Decision Density

Acoplamento

•AC – Aferent Coupling

•EC – Eferent Coupling

•ABC – Association Between Classes

Coesão

•LCOM – Lack of Cohesion Methods

•LCOM-HS - Lack of Cohesion Of Methods Henderson-Sellers

Herança

•NOC - Number of Children

•DIT - Depth of Inheritance Tree

Other Metrics

•Churn

•Program Vocabulary

•...

Software Product Metrics

How to Deal With Lots Of Data?

Metrics Analysis – Dashboards (Sonar)

Metrics Analysis – Temporal Series

Metrics Analysis - Control Charts

Metrics Analysis - OLAP

Metrics Analysis – Indicators from DW

Build Definition

Going Deeper

I need some help!

Roberto Pepato Mellado rpepato@gmail.com

@rpepato

Gabriel Moreira gabrielspmoreira@yahoo.com.br

@gspmoreira

http://workingsweng.wordpress.com/

19 e 20 de Agosto de 2011

http://www.agilevale.com.br/ @agilevale #agilevale