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As users’ requirements change in today’s fast-paced business market, computer software has to adapt to new hardware, technologies and requirements to keep up with the trend. Therefore, to avoid depreciation and obsolescence, which can have detrimental effects on a product, software needs to be constantly maintained and, when passed a certain point in its lifecycle, needs to be migrated or re-developed from scratch. Automated migration enables software vendors to decrease the cost of the migration process by source code generation. However, as security is a crucial requirement in any system, it is not guaranteed that the previously satisfied security requirements are satisfied in the migrated software. Therefore, it is critical to study the evolution of security throughout the automated migration process to predict where new security vulnerabilities may emerge and to understand the scale on which the security is affected. Thesis Master of Applied Science (MASc)

Awareness of the importance of systems and software traceability and tool support for traceability have improved over the years. However, an effective traceability solution must align with an organization's engineering processes. Specifically, the phases of the traceability process model (traceability strategy, creation, use and maintenance of traceability) must be aligned with the organization's engineering processes. Previous research has discussed the benefits of integrating traceability into the configuration management process. This research proposes a process based on Model-Driven Engineering (MDE) where traceability is integrated into Change Request (CR) management. In this process, traceability is managed with the status of the CR; for example, traceability is used to report the progress of the implementation of a CR. The proof of concept of the integrated process is demonstrated with a tool, Traceability Centric Issue Tracking System (TraceITS), based on Eclipse Modelling Tools and Epsilon model management framework. A preliminary evaluation of TraceITS indicates several advantages over regular ITS. Thesis Master of Applied Science (MASc)

Numerous programming languages have been proposed over the last 60 years. Programming languages, like other software systems, can become obsolete: their compilers, virtual machines, interpreters and libraries are no longer fit for purpose. As such, programs written using obsolete programming languages may need to be modernized, relying instead on modern languages, libraries and tools. Modernization is both a technical and social process; in this thesis, we focus on the technical aspects of modernization, particularly software migration, wherein a program written in one programming language is transformed into an equivalent or similar program written in a different language. Migration happens because many software systems that were developed decades ago can no longer be maintained and need to be overhauled to make it possible to implement new processes that can take advantage of new technologies recently developed. Migrating an existing codebase to a more efficient and modern programming language is often expensive, and there are different types of risks involved; for example, many functionalities may not be implemented properly after migration, i.e., the migration is inaccurate; or concerns for code quality may not be considered until the end of the migration; and for large code bases, the migration process may be slow, and may demand substantial resources to implement. Recent advancements in Artificial Intelligence in natural language translation have been widely accepted but their application to programming language translation have been limited due to the scarcity of parallel data (i.e., the collection of equivalent phrases in source language and their translations in a target language). This thesis explores a preliminary investigation into the use of unsupervisedlearning methods – specifically, a newly proposed K-Means clustering approach for preprocessing and analyzing the source code – prior to rule-based code translation. The thesis investigates such a process both generally and abstractly, and specifically, in the context of a concrete migration from C++ to Java. The thesis also presents a test set for evaluating such an approach, based on open source, which can be used as a general resource for both validating migration approaches and assessing their performance. The test results and our experiments show that our proposed translation approach based on unsupervised machine learning for preprocessing has a very good translation accuracy score of 77.89% and 81.34% when compared against an alternative approach with accuracy score of 33.24% and 59.96%, and also when compared with rule-based translation that excludes the preprocessing step with accuracy score 37.39% and 41.26%. Thesis Master of Science (MSc)

Security decisions are an important part of software architecture design, and thus deserve to be explicitly represented in the design documentation. While UML is the best-known language for creating such documentation, it lacks security specific notations, which makes it difficult to represent the effect of the security decisions. Several security extensions for UML exist in the literature, but they represent security concerns at a lower level of abstraction, or only support a limited subset of security concerns. We propose a new notation, MASC, to model security concerns at the architectural level. It has been designed as an extension of UML, and is based on recurring security concepts that have been distilled from well-known security principles, goals, and patterns. By using our notation, a designer obtains a technique to express security concerns more explicitly in the architectural design documentation. ispartof: pages:36-41 ispartof: 2015 IEEE/ACM 7th International Workshop on Modeling in Software Engineering (MiSE) vol:7 pages:36-41 ispartof: Modelling in Software Engineering (MiSE) location:Florence date:16 May - 17 May 2015 status: published

Context: Despite model querying being an important practical problem, existing solutions lack either usability, expressiveness, or generality. The Visual Model Query Language (VMQL) is a query byexample solution created to satisfy these requirements simultaneously. Objective: In the present paper we study whether VMQL queries can be executed in an e_cient way, such that VMQL is suitable for ad-hoc model querying in practical settings involving large models. Method: We study VMQL query execution performance on sets of models ranging over a broad spectrum of sizes and degrees of complexity. The models are based on large and realistic case studies. Results: We observe that our approach exhibits competitive performance, while providing superior usability and generality.

Traceability data provides the knowledge on dependencies and logical relations existing amongst artefacts that are created during software development. In reasoning over traceability data, conclusions can be drawn to increase the quality of software. The paradigm of Model-driven Software Engineering (MDSD) promotes the generation of software out of models. The latter are specified through different modelling languages. In subsequent model transformations, these models are used to generate programming code automatically. Traceability data of the involved artefacts in a MDSD process can be used to increase the software quality in providing the necessary knowledge as described above. Existing traceability solutions in MDSD are based on the integral model mapping of transformation execution to generate traceability data. Yet, these solutions still entail a wide range of open challenges. One challenge is that the collected traceability data does not adhere to a unified formal definition, which leads to poorly integrated traceability data. This aggravates the reasoning over traceability data. Furthermore, these traceability solutions all depend on the existence of a transformation engine. However, not in all cases pertaining to MDSD can a transformation engine be accessed, while taking into account proprietary transformation engines, or manually implemented transformations. In these cases it is not possible to instrument the transformation engine for the sake of generating traceability data, resulting in a lack of traceability data. In this work, we address these shortcomings. In doing so, we propose a generic traceability framework for augmenting arbitrary transformation approaches with a traceability mechanism. To integrate traceability data from different transformation approaches, our approach features a methodology for augmentation possibilities based on a design pattern. The design pattern supplies the engineer with recommendations for designing the traceability mechanism and for modelling traceability data. Additionally, to provide a traceability mechanism for inaccessible transformation engines, we leverage parallel model matching to generate traceability data for arbitrary source and target models. This approach is based on a language-agnostic concept of three similarity measures for matching. To realise the similarity measures, we exploit metamodel matching techniques for graph-based model matching. Finally, we evaluate our approach according to a set of transformations from an SAP business application and the domain of MDSD.

Model-driven software development (MDSD) and component-based software development are both paradigms for reducing complexity and for increasing abstraction and reuse in software development. In this thesis, we aim at combining the advantages of each by introducing methods from component-based development into MDSD. In MDSD, all artefacts that describe a software system are regarded as models of the system and are treated as the central development artefacts. To obtain a system implementation from such models, they are transformed and integrated until implementation code can be generated from them. Models in MDSD can have very different forms: they can be documents, diagrams, or textual specifications defined in different modelling languages. Integrating these models of different formats and abstraction in a consistent way is a central challenge in MDSD. We propose to tackle this challenge by explicitly separating the tasks of defining model components and composing model components, which is also known as distinguishing programming-in-the-small and programming-in-the-large. That is, we promote a separation of models into models for modelling-in-the-small (models that are components) and models for modelling-in-the-large (models that describe compositions of model components). To perform such component-based modelling, we introduce two architectural styles for developing systems with component-based MDSD (CB-MDSD). For CB-MDSD, we require a universal composition technique that can handle models defined in arbitrary modelling languages. A technique that can handle arbitrary textual languages is universal invasive software composition for code fragment composition. We extend this technique to universal invasive software composition for graph fragments (U-ISC/Graph) which can handle arbitrary models, including graphical and textual ones, as components. Such components are called graph fragments, because we treat each model as a typed graph and support reuse of partial models. To put the composition technique into practice, we developed the tool Reuseware that implements U-ISC/Graph. The tool is based on the Eclipse Modelling Framework and can therefore be integrated into existing MDSD development environments based on the framework. To evaluate the applicability of CB-MDSD, we realised for each of our two architectural styles a model-driven architecture with Reuseware. The first style, which we name ModelSoC, is based on the component-based development paradigm of multi-dimensional separation of concerns. The architecture we realised with that style shows how a system that involves multiple modelling languages can be developed with CB-MDSD. The second style, which we name ModelHiC, is based on hierarchical composition. With this style, we developed abstraction and reuse support for a large modelling language for telecommunication networks that implements the Common Information Model industry standard.

Providing support for reversible transformations as a basis for round-trip engineering is a significant challenge in model transformation research. While there are a number of current approaches, they require the underlying transformation to exhibit an injective behaviour when reversing changes. This however, does not serve all practical transformations well. In this paper, we present a novel approach to round-trip engineering that does not place restrictions on the nature of the underlying transformation. Based on abductive logic programming, it allows us to compute a set of legitimate source changes that equate to a given change to the target model. Encouraging results are derived from an initial prototype that supports most concepts of the Tefkat transformation language