Das SCCH ist eine Initiative der Das SCCH befindet sich im

Empirical Evaluation of Strategies to Detect Logical Change Dependencies

SOFSEM 2010

Günter Pirkblauer

+43 7236 3343 853guenter.pirklbauer@scch.atwww.scch.at

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Overview

Introduction Motivation of Research Evaluation Approach Strategies Results Discussion

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Introduction

Software Maintenance Life cycle of software systems comprises not only the

analysis-, design- and development phases, but also the maintenance.

Exceed 75% of the all over development costs (up to 95%)

In Software Maintenance, all is about Changes New requirements changes in the system

Changes increase the complexity

Changes often lead to new errors

need to perform Change Impact Analysis

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Introduction

Change Impact Analysis „… identifiying the potential consequence of a change, or

estimated what needs to be modified to accomplish a change …“ [ArnoldBohner1996]

… is more a discipline than an approach

… needs the identification of artifacts and dependencies

General Approaches/Principles: Software Traceability and Dependency Analysis (in consequence: Software Evolution Analysis, Change Coupling Analysis, …)

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R1

R2

R3

R4

Requirements Design Code

D1

D2

D3

D4

C1

C2

C3

C4

Introduction

Software TraceabilityDependency Analysis (static/dynamic)

Cha

nge

Cou

plin

g A

naly

sis

Approaches

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Introduction

Change Coupling Analysis … try to detect logical change dependencies of artifacts

based on co-changes in the versioning system

… are relevant for change impact analysis, because they enlarge physical dependencies (e.g. static code analysis) analysis of check-ins of developers

especiallly transactions, time, comments, users, …

… need strategies (algorithm, patterns) to detect change couplings

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Auswirkungsanalysen-Client, Visualisierung

CVS

ClearCase

Subversion

PVCS

Parser-Core (Konfiguration)

ParserDatenquellenOperativen VS-Daten

(XML oder DB)

Depedency-Detektor

Konfiguration

instanziert

Parser-Core (Konfiguration)

Konfiguration

XML, Property-Files

XML Property-Files

Data Warehouse

C: 2 R: 4X: 7

C: 1 R: 2X: 4 C: 2

R: 4X: 7

C: 1 R: 2X: 4Serverlogs

(z.B. TA2-Anwendung)

instanziert

Datenquellen Parser Operativen Logdaten

Depedency-Detektor

ciamss_core_ data ciamss_dwh

Transformation

ETL

Artefakt-Identifier(Kategorisierung v.

Artefakten)

OLAP-Tool

0102030405060708090

1st Qtr

2nd Qtr

3rd Qtr

4th Qtr

ciamss_core_ data

ciamss_core_ data

Ver

sion

ieru

ngss

yste

m-D

aten

Ser

verlo

g-D

aten

Introduction: CIA-Framework

Strategies!

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Introduction: The CIA-Framework

Change Impact Analysis … it looks like:

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Motivation of Research

Strategies are based on typical project scenarios Analysis of project scenarios (learning, how developers do

their job) Identification of strategies

Literature Analysis Implementing strategies in a framework Empirical evaluation of strategies

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Evaluation Approach

Evaluation of 2 projects Determine the quantities of dependencies Analyzing the „contribution“ of each strategy Analyzing overlappings of results

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Study Approach

2 Projects

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Strategies

Transaction-based Strategy Comment-based Strategy Change-ID-based-Strategy Change-Hierarchy-based Strategy

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Strategies

Transaction-based Strategy

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Strategies

Comment-based Strategy

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Strategies

Change-ID-based-Strategy

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Strategies

Change-Hierarchy-based Strategy Data from outside the Versioning-System Database

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Results

Project 1

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Results

Project 2

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Discussion

Distribution of Dependencies

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Discussion

Unique and Overlapping Dependency Results Transaction-based Dependencies are completely covered by

other strategies (mostly Comment-based Dep.) Change-hierarchy-based Dep. have overlappings with

Transaction-based- and ChangeID-based Dependencies Majority of Change-hierarchy-based dependencies are

unique

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Discussion

Ratio of Check-ins with Change-ID and Change-ID based Dependencies Coherence between Change-IDs and Change-ID based

Dependencies (Project 1: 46%/55,6%, Project 2: 7%/3,5%) Change-ID based dependencies are high reliable Benefit of integrated IDEs like Eclipse (programming, bug-

and change-tracking, versioning system) for Change Impact Analysis

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Thank you!