Zielorientierte Erkennung und Behebung von Qualitätsdefiziten in Software-Systemen am Beispiel der Weiterentwicklungsfähigkeit

The evolvability of software systems is one of the key issues when considering their long term quality. Continuous changes and extensions of these systems are neccessary to adjust them to new or changing requirements. But the changes often cause quality deficiencies, which lead to an increase in complexity or an architectural decay. Especially quality deficiencies within the specification or the architecture of a software system can heavily impair a software system. To counteract this, a method is developed in this work to support the analysis of a quality goal in order to identify the quality deficiencies which hinder the achievement of the quality goal. Both the detection and the removal of quality deficiencies are accomplished in a systematic way. The method integrates detection of these quality deficiencies and their removal by reengineering activities based on rules. The detection of quality deficiencies is performed by means of measurable quality attributes which are derived from a quality goal, such as evolvability. In order to demonstrate the practicability of the method, the quality goal evolvability is taken as an example. This work shows how a software system can be evaluated with regard to evolvability based on structural dependencies and which reengineering activities will improve the system in the direction of this quality goal. To evaluate the method, it was applied within an industrial case study. By analyzing the given software system a large number of different quality deficiencies were detected. Afterwards the system’s evolvability was improved substantially by reengineering activities proposed by the method. Abkürzungsund Symbolverzeichnis Abkürzungen FCM Factor Criteria Metrics FDD Feature Driven Development DSL Domain Specific Language GQM Goal Question Metric KLOC Thousands of Lines of Code SLOC Source Lines of Code SIG Softgoal Interpendency Graph OML OPEN Modeling Language OOSE Object Oriented Software Engineering OPEN Object Oriented Process, Environment, and Notation QMOOD Quality Model of Object Oriented Design RUP Rational Unified Prozess UML Unified Modeling Language Symbole typ → Beziehung mit Beziehungstyp i → Implementiert-Beziehung b → Benutzt-Beziehung (engl. Usage-Beziehung) t → Teil-von-Beziehung r → Realisiert-durch-Beziehung e → Erweitert-Beziehung Lateinische Buchstaben E Entitäten eines Software-Systems F Entitätstyp Feature eines Software-Systems A Entitätstyp Architekturkomponente eines Software-Systems S Entitätstyp Schnittstelle eines Software-Systems K Entitätstyp Klasse eines Software-Systems D Entitätstyp Datendatei (zur Konfiguration) eines Software-Systems