Feature-based methodology for supporting architecture refactoring and maintenance of long-life software systems

Zusammenfassung Langlebige Software-Systeme durchlaufen viele bedeutende Veraenderungen im Laufe ihres Lebenszyklus, um der Weiterentwicklung der Problemdomaenen zu folgen. Normalerweise ist es schwierig eine Software-Systemarchitektur den schnellen Weiterentwicklungen einer Problemdomaene anzupassen und mit der Zeit wird der Unterschied zwischen der Problemdomaene und der Software-Systemarchitektur zu groß, um weitere Softwareentwicklung sinnvoll fortzufuehren. Fristgerechte Refactorings der Systemarchitektur sind notwendig, um dieses Problem zu vermeiden. Aufgrund des verhaeltnismaeßig hohen Gefahrenpotenzials und des zeitlich stark verzoegerten Nutzens von Refactorings, werden diese Maßnahmen normalerweise bis zum letztmoeglichen Zeitpunkt hinausgeschoben. In der Regel ist das Management abgeneigt Architektur-Refactorings zu akzeptieren, außer diese sind absolut notwendig. Die bevorzugte Vorgehensweise ist, neue Systemmerkmale ad hoc hinzuzufuegen und nach dem Motto ”Aendere nie etwas an einem funktionierenden System!” vorzugehen. Letztlich ist das Ergebnis ein Architekturzerfall (Architekturdrift). Die Notwendigkeit kleiner Refactoring-Schritte fuehrt zur Notwendigkeit des Architektur-Reengineerings. Im Gegensatz zum Refactoring, das eine normale Entwicklungstaetigkeit darstellt, ist Reengineering eine Form der Software- ”Revolution”. Reengineeringprojekte sind sehr riskant und kostspielig. Der Nutzen des Reengineerings ist normalerweise nicht so hoch wie erwartet. Wenn nach dem Reengineering schließlich die erforderlichen Architekturaenderungen statt.nden, kann dies zu spaet sein. Trotz der enormen in das Projekt gesteckten Bemuehungen erfuellen die Resultate des Reengineerings normalerweise nicht die Erwartungen. Es kann passieren, dass sehr bald ein neues, kostspieliges Reengineering erforderlich wird. In dieser Arbeit werden das Problem der Softwareevolution und der Zerfall von Softwarearchitekturen behandelt. Eine Methode wird vorgestellt, welche die Softwareentwicklung in ihrer entscheidenden Phase, dem Architekturrefactoring, unterstuetzt. Die Softwareentwicklung wird sowohl in technischer als auch organisatorischer Hinsicht unterstuetzt. Diese Arbeit hat neue Techniken entwickelt, welche die Reverse-Engineering-, Architecture-Recovery- und Architecture-Redesign-Taetigkeiten unterst uetzen. Sie schlaegt auch Aenderungen des Softwareentwicklungsprozesses vor, die fristgerechte Architekturrefactorings erzwingen koennen und damit die Notwendigkeit der Durchfuehrung eines Architektur- Reengineerings vermeiden. In dieser Arbeit wird die Merkmalmodellierung als Hauptinstrument verwendet. Merkmale werden genutzt, um die Abstraktionsluecke zwischen den Anforderungen der Problemdomaene und der Systemarchitektur zu fuellen. Merkmalmodelle werden auch als erster Grundriss fr die Wiederherstellung der verlorenen Systemarchitektur genutzt. Merkmalbasierte Analysen fuehren zu diversen, nuetzlichen Hinweisen fuer den erneuten Entwurf (das Re-Design) einer Architektur. Schließlich wird die Merkmalmodellierung als Kommunikationsmittel zwischen unterschiedlichen Projektbeteiligten (Stakeholdern) im Verlauf des Softwareengineering-Prozesses verwendet und auf dieser Grundlage wird ein neuer Anforderungsde.nitionsprozess vorgeschlagen, der die erforderlichen Architekturrefactorings erzwingt.The long-life software systems withstand many significant changes throughout their life-cycle in order to follow the evolution of the problem domains. Usually, the software system architecture can not follow the rapid evolution of a problem domain and with time, the diversion of the architecture in respect to the domain features becomes prohibiting for software evolution. For avoiding this problem, periodical refactorings of the system architecture are required. Usually, architecture refactorings are postponed until the very last moment, because of the relatively high risk involved and the lack of short-term profit. As a rule, the management is unwilling to accept architecture refactorings unless they become absolutely necessary. The preferred way of working is to add new system features in an ad-hoc manner and to keep the rule ”Never touch a running system!”. The final result is an architecture decay. The need of performing small refactoring activities turns into need for architecture reengineering. In contrast to refactoring, which is a normal evolutionary activity, reengineering is a kind of software ”revolution”. Reengineering projects are risky and expensive. The effectiveness of reengineering is also usually not as high as expected. When finally after reengineering the required architecture changes take place, it can be too late. Despite the enormous invested efforts, the results of the reengineering usually do not satisfy the expectations. It might happen that very soon a new expensive reengineering is required. This thesis deals with the problem of software evolution and the decay of software architectures. It presents a method, which assists software evolution in its crucial part, the architecture refactoring. The assistance is performed for both technical and organizational aspects of the software evolution. The thesis provides new techniques for supporting reverse engineering, architecture recovery and redesigning activities. It also proposes changes to the software engineering process, which can force timely architecture refactorings and thus avoid the need of performing architecture reengineering. For the work in this thesis feature modeling is utilized as a main asset. Features are used to fill the abstraction gap between domain requirements and system architecture. Feature models are also used as an outline for recovering of lost system architectures. Through feature-based analyses a number of useful hints and clues for architecture redesign are produced. Finally, feature modeling is used as a communication between different stakeholders of the software engineering process and on this basis a new requirements engineering process is proposed, which forces the needed architecture refactorings

Assessing architectural evolution: A case study

This is the post-print version of the Article. The official published can be accessed from the link below - Copyright @ 2011 SpringerThis paper proposes to use a historical perspective on generic laws, principles, and guidelines, like Lehman’s software evolution laws and Martin’s design principles, in order to achieve a multi-faceted process and structural assessment of a system’s architectural evolution. We present a simple structural model with associated historical metrics and visualizations that could form part of an architect’s dashboard. We perform such an assessment for the Eclipse SDK, as a case study of a large, complex, and long-lived system for which sustained effective architectural evolution is paramount. The twofold aim of checking generic principles on a well-know system is, on the one hand, to see whether there are certain lessons that could be learned for best practice of architectural evolution, and on the other hand to get more insights about the applicability of such principles. We find that while the Eclipse SDK does follow several of the laws and principles, there are some deviations, and we discuss areas of architectural improvement and limitations of the assessment approach

Competitiveness and sustainability in tourism industry: the "albergo diffuso" case study

The objective of the analysis developed in this paper is to verify whether the sustainability of the hotel ospitality model contributes to the competitiveness of tourist destinations. The research question is: does the model of “albergo diffuso” satisfy the requirement for a social, economic and environmental sustainability? The research method adopted consisted in a survey with the submission of a questionnaire to a number of alberghi diffusi operating worldwide, that is 130 units of analysis. The submission period went from October to December 2016. Through the questionnaire submitted to the interviewees it has been possible to analyze the motivation for the business start-up as well as the characteristics of the entrepreneur, the managerial systems and the governance style. The results will be analyzed through the application of the Weaver model (2014; 2017) which is considered essential to evaluate the contribution of the albergo diffuso to tourism sustainability. The implementation of the Weaver matrix to evaluate the contribution of the albergo diffuso to the sustainability of a tourist destination is the original element of the paper. The paper discusses the implications of sustainability with particular regards to the “albergo diffuso”. Therefore, it would be suitable to expand the analysis to additional models of tourist hospitality present in the international tourism scenario

Iterative criteria-based approach to engineering the requirements of software development methodologies

Software engineering endeavours are typically based on and governed by the requirements of the target software; requirements identification is therefore an integral part of software development methodologies. Similarly, engineering a software development methodology (SDM) involves the identification of the requirements of the target methodology. Methodology engineering approaches pay special attention to this issue; however, they make little use of existing methodologies as sources of insight into methodology requirements. The authors propose an iterative method for eliciting and specifying the requirements of a SDM using existing methodologies as supplementary resources. The method is performed as the analysis phase of a methodology engineering process aimed at the ultimate design and implementation of a target methodology. An initial set of requirements is first identified through analysing the characteristics of the development situation at hand and/or via delineating the general features desirable in the target methodology. These initial requirements are used as evaluation criteria; refined through iterative application to a select set of relevant methodologies. The finalised criteria highlight the qualities that the target methodology is expected to possess, and are therefore used as a basis for de. ning the final set of requirements. In an example, the authors demonstrate how the proposed elicitation process can be used for identifying the requirements of a general object-oriented SDM. Owing to its basis in knowledge gained from existing methodologies and practices, the proposed method can help methodology engineers produce a set of requirements that is not only more complete in span, but also more concrete and rigorous

Some issues in the 'archaeology' of software evolution

During a software project's lifetime, the software goes through many changes, as components are added, removed and modified to fix bugs and add new features. This paper is intended as a lightweight introduction to some of the issues arising from an `archaeological' investigation of software evolution. We use our own work to look at some of the challenges faced, techniques used, findings obtained, and lessons learnt when measuring and visualising the historical changes that happen during the evolution of software

Some issues in the 'archaeology' of software evolution

During a software project's lifetime, the software goes through many changes, as components are added, removed and modified to fix bugs and add new features. This paper is intended as a lightweight introduction to some of the issues arising from an `archaeological' investigation of software evolution. We use our own work to look at some of the challenges faced, techniques used, findings obtained, and lessons learnt when measuring and visualising the historical changes that happen during the evolution of software

The Country-specific Organizational and Information Architecture of ERP Systems at Globalised Enterprises

The competition on the market forces companies to adapt to the changing environment. Most recently, the economic and financial crisis has been accelerating the alteration of both business and IT models of enterprises. The forces of globalization and internationalization motivate the restructuring of business processes and consequently IT processes. To depict the changes in a unified framework, we need the concept of Enterprise Architecture as a theoretical approach that deals with various tiers, aspects and views of business processes and different layers of application, software and hardware systems. The paper outlines a wide-range theoretical background for analyzing the re-engineering and re-organization of ERP systems at international or transnational companies in the middle-sized EU member states. The research carried out up to now has unravelled the typical structural changes, the models for internal business networks and their modification that reflect the centralization, decentralization and hybrid approaches. Based on the results obtained recently, a future research program has been drawn up to deepen our understanding of the trends within the world of ERP systems.Information System; ERP; Enterprise Resource Planning; Enterprise Architecture; Globalization; Centralization; Decentralization; Hybrid