Portability of Process-Aware and Service-Oriented Software : Evidence and Metrics

Faculty/Professorship: Distributed Systems  
Author(s): Lenhard, Jörg
Corporate Body: Otto-Friedrich-Universität Bamberg, Fakultät Wirtschaftsinformatik und Angewandte Informatik
Publisher Information: Bamberg : University of Bamberg Press
Year of publication: 2016
Pages: XVIII, 304
ISBN: 978-3-86309-399-0
Series ; Volume: Schriften aus der Fakultät Wirtschaftsinformatik und Angewandte Informatik der Otto-Friedrich-Universität Bamberg ; 23 
Supervisor(s): Wirtz, Guido  ; Dustdar, Schahram
Source/Other editions: Parallel erschienen als Druckausg. in der University of Bamberg Press, 2016 (22,00 EUR)
Language(s): English
Zugl.: Bamberg, Univ., Diss.
Link to order the print version: http://www.uni-bamberg.de/ubp/
Licence: German Act on Copyright 
URN: urn:nbn:de:bvb:473-opus4-462521
Modern software systems are becoming increasingly integrated and are required to operate over organizational boundaries through networks. The development of such distributed software systems has been shaped by the orthogonal trends of service-orientation and process-awareness. These trends put an emphasis on technological neutrality, loose coupling, independence from the execution platform, and location transparency. Execution platforms supporting these trends provide context and cross-cutting functionality to applications and are referred to as engines.
Applications and engines interface via language standards. The engine implements a standard. If an application is implemented in conformance to this standard, it can be executed on the engine. A primary motivation for the usage of standards is the portability of applications. Portability, the ability to move software among different execution platforms without the necessity for full or partial reengineering, protects from vendor lock-in and enables application migration to newer engines.
The arrival of cloud computing has made it easy to provision new and scalable execution platforms. To enable easy platform changes, existing international standards for implementing service-oriented and process-aware software name the portability of standardized artifacts as an important goal. Moreover, they provide platform-independent serialization formats that enable the portable implementation of applications. Nevertheless, practice shows that service-oriented and process-aware applications today are limited with respect to their portability. The reason for this is that engines rarely implement a complete standard, but leave out parts or differ in the interpretation of the standard. As a consequence, even applications that claim to be portable by conforming to a standard might not be so.
This thesis contributes to the development of portable service-oriented and process-aware software in two ways: Firstly, it provides evidence for the existence of portability issues and the insufficiency of standards for guaranteeing software portability. Secondly, it derives and validates a novel measurement framework for quantifying portability. We present a methodology for benchmarking the conformance of engines to a language standard and implement it in a fully automated benchmarking tool. Several test suites of conformance tests for two different languages, the Web Services Business Process Execution Language 2.0 and the Business Process Model and Notation 2.0, allow to uncover a variety of standard conformance issues in existing engines. This provides evidence that the standard-based portability of applications is a real issue. Based on these results, this thesis derives a measurement framework for portability. The framework is aligned to the ISO/IEC Systems and software Quality Requirements and Evaluation method, the recent revision of the renowned ISO/IEC software quality model and measurement methodology. This quality model separates the software quality characteristic of portability into the subcharacteristics of installability, adaptability, and replaceability. Each of these characteristics forms one part of the measurement framework. This thesis targets each characteristic with a separate analysis, metrics derivation, evaluation, and validation. We discuss existing metrics from the body of literature and derive new extensions speciffically tailored to the evaluation of service-oriented and process-aware software. Proposed metrics are defined formally and validated theoretically using an informal and a formal validation framework. Furthermore, the computation of the metrics has been prototypically implemented. This implementation is used to evaluate metrics performance in experiments based on large scale software libraries obtained from public open source software repositories.
In summary, this thesis provides evidence that contemporary standards and their implementations are not sufficient for enabling the portability of process-aware and service-oriented applications. Furthermore, it proposes, validates, and practically evaluates a framework for measuring portability.
GND Keywords: Portabilität; Prozessmanagement; Softwareentwicklung; Serviceorientierte Architektur
Keywords: Portability, Service-Orientation, Process-Awareness, Software Metrics
DDC Classification: 004 Computer science  
RVK Classification: ST 230   
Type: Doctoralthesis
URI: https://fis.uni-bamberg.de/handle/uniba/40174
Year of publication: 25. April 2016

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