Context. Variability management (VM) in automotive domain is a promising solution to reduction of complexity. Feature modeling, as starting point of VM, deals with analysis and representation of available features in terms of commonalities and variabilities. The work is done in the context of an automotive industry – Adam Opel AG. Objectives. This work studies the automotive specific problems with respect to feature modeling, investigates what decomposition and structuring approaches exist in literature, and which one of them satisfies the industrial requirements. The approach to feature modeling is synthesized, evaluated and documented. Methods. In this work a case study with survey and literature review is performed. Survey uses semi structured interview and workshops as data collection methods. Systematic review includes articles from Compendex, Inspec, IEEE Xplore, ACM Digital Library, Science Direct and Engineering Village. Approach selection is based on mapping requirements against discovered approaches and discussion with industry practitioner on the regular meetings. Evaluation is proposed according to Goal Question Metric paradigm. Results. The approach that can be followed in the case organization is described and evaluated. The reasoning behind feature modeling approach construction and selection can be generalized for other organizations as well. Conclusions. We conclude that there is no perfect approach that would solve all the problems connected to automotive software. However, structuring approaches can be complementary and while combining give a good results. Tool support that integrates into the whole development cycle is important, as the amount of information cannot be processed using simple feature modeling tools. There is a need for further investigation in both directions – tool support and structuring approaches. The tactics that are proposed here should be introduced in organizations and formally evaluated. / Tel. +4917661965859

<p>Variability in complex systems offering rich set of features is a seriouschallenge to their users in term of flexibility with many possible variants fordifferent application contexts and maintainability. During the long period oftime, much effort has been made to deal with these issues. An effort in thisregard is developing and implementing different variability modelingtechniques.This thesis argues the explanation of three modeling techniques namedconfigurable components, feature models and function-means trees. The maincontribution to the research includes:• A comparison of above mentioned variability modeling techniques in asystematic way,• An attempt to find the integration possibilities of these modelingtechniques based on literature review, case studies, comparison,discussions, and brainstorming.The comparison is based on three case studies each of which is implemented inall above mentioned three modeling techniques and a set of generic aspects ofthese techniques which are further divided into characteristics. At the end, acomprehensive discussion on the comparison is presented and in final sectionsome integration possibility are proposed on the basis of case studies,characteristics, commonalities and experience gained through theimplementation of case studies and literature review.</p>

This thesis provides an approach to use feature modeling with a set of guidelines for requirements definition and decomposition activities of the axiomatic design methodology. A tool that supports the development of feature models and modeling of the Axiomatic Design activities is implemented to be utilized for guiding the designer. Axiomatic Design suggested four domains of information in the transformation of the problem definition to the solution, and provided mechanisms for supporting the mapping among some of those domains. The approach suggested in this thesis fills an important gap, which is the transition from the customer needs to functional requirements, in axiomatic design. A case study is carried out in order to analyze advantages and disadvantages of the proposed approach.

Feature modeling is a common way of representing commonality and variability in Software Product Lines. There are alternative notations reported in the literature to represent feature models. Compared to the graphical notations, the text-based notations are more amenable to automated processing and tool interoperability. This study presents an XML-based feature modeling language to represent extended feature models that can include complex relationships involving attributes. We first provide a Context Free Grammar for the extended feature model definitions including such complex relationships. Then we build the XML Schema Definitions and present a number of XML instances in accordance with the defined schema. In addition, we discuss a validation process for the validation of the XML instances against the defined schema, which also includes additional tasks such as well-formedness checking for the XML instances.

This work introduces a combination of image processing and analysis methods that perform feature extraction, shape analysis and tomographic reconstruction of Electron Microscopy images. These have been implemented on images of the AIDS virus interacting with neutralizing molecules. The AIDS virus spike is the primary target of drug design as it is directly involved in infecting host cells. First, a fully automated technique is introduced that can extract sub-volumes of the AIDS virus spike and be used to build a statistical model without the need for any user supervision. Such an automatic feature extraction method can significantly enhance the overall process of shape analysis of the AIDS virus spike imaged through the electron microscope. Accurate models of the virus spike will help in the development of better drug design strategies. Secondly, a tomographic reconstruction method implemented using a shape based regularization technique is introduced. Spatial models of known features in the structure being reconstructed are integrated into the reconstruction process as regularizers. This regularization scheme is driven locally through shape information obtained from segmentation and compared with a known spatial model. This method shows reduced blurring, and an improvement in the resolution of the reconstructed volume was also measured. It performs better than popular current techniques and can be extended to other tomographic modalities. Improved Electron Tomography reconstructions will provide better structure elucidation and improved feature visualization, which can aid in solving key biological issues. / text

Programų sistemų kūrimas, kai yra daug užsakovų, kurių reikalavimai skiriasi, yra sudėtingas procesas ir reikalauja aprašyti galimus programų sistemos variantus. Programų variantiškumui aprašyti naudojami kuriamos sistemos požymių modeliai. Sistemos požymių modeliavimas yra svarbus variantiškumo aprašymo metodas. Sistemos požymių variantiškumo modeliai aprašo aibę programų sistemų, kurios dar vadinamos programų sistemų linija. Programų sistemų linija yra eilė panašių programų kurios dalinasi bendrais atributais. Tiksliau apibūdinti programų sistemų linijai yra nustatomi sistemų atributai ir jų tarpusavio sąryšiai, jie yra pavaizduojami požymių diagramose. Požymis tai savitas, charakteringas sistemos atributas, kuris nusako matomus sistemos atributus, tačiau nesigilina į detalų sistemos apibūdinimą. Greitam ir kokybiškam programų sistemos variantiškumo modeliavimui reikalingas geras įrankis. Tam skirtas požymių diagramų modeliavimo įrankis, nes sukurti požymių modeliai yra informatyvūs ir gali lengvai perteikti sistemos variantiškumo informaciją. Tačiau programų sistemos požymių diagrama neturi techninės informacijos, kuri yra reikalinga programos kūrimui. Ši informacija yra saugoma UML modeliuose. Programos UML modelį galima išplėsti variantiškumo informacija, papildant jį sistemos požymių modelio informacija. Magistrinio projekto metu buvo sukurtas įrankis (FD2), kuris įgyvendina požymių diagramos susiejimą su UML klasių diagrama. Magistriniame darbe tiriamas sistemų... [toliau žr. visą tekstą] / Feature modeling is important approach to deal system variability at higher abstraction level. Variability models define the variability of a software product line. Unfortunately, it is not integrated into a modeling framework like the Unified Modeling Language (UML). To use it in conjunction with UML, it is important to integrate feature modeling into UML. This thesis describes the way how feature variability models can be linked with existing UML models and how it is done in the feature modeling tool FD2. The feature modeling tool is described and the complete example provided. Chapter 2 discusses the way of Feature model integration with UML model. Chapter 3 describes the implementation of FD2 tool. Chapter 4 discusses the advantages and disadvantages of FD2 tool. Chapter 5 provides examples and discusses their results. In conclusion this thesis propose feature modeling integration with UML modeling, discusses the program developed during master project, provides 2 examples and discusses their results, points out some issues requiring further work.

Context: A common way to represent product lines is with variability modeling. Yet, there are different ways to extract and organize relevant characteristics of variability. Comprehensibility of these models and the ease of creating models are important for the efficiency of any variability management approach. Objective: The goal of this paper is to investigate the comprehensibility of two common styles to organize variability into models - hierarchical and constrained - where the dependencies between choices are specified either through the hierarchy of the model or as cross-cutting constraints, respectively. Method: We conducted a controlled experiment with a sample of 90 participants who were students with prior training in modeling. Each participant was provided with two variability models specified in Common Variability Language (CVL) and was asked to answer questions requiring interpretation of provided models. The models included 9 to 20 nodes and 8 to 19 edges and used the main variability elements. After answering the questions, the participants were asked to create a model based on a textual description. Results: The results indicate that the hierarchical modeling style was easier to comprehend from a subjective point of view, but there was also a significant interaction effect with the degree of dependency in the models, that influenced objective comprehension. With respect to model creation, we found that the use of a constrained modeling style resulted in higher correctness of variability models. Conclusions: Prior exposure to modeling style and the degree of dependency among elements in the model determine what modeling style a participant chose when creating the model from natural language descriptions. Participants tended to choose a hierarchical style for modeling situations with high dependency and a constrained style for situations with low dependency. Furthermore, the degree of dependency also influences the comprehension of the variability model.

In this thesis, we present mixsets, an approach to combine annotative and compositional fragments for specifying code variants to form software product lines (SPLs). There are three key contributions of our research: introducing mixsets to represent software variability, extending mixsets to construct feature models, and improving software composition to achieve fine-grained variability. The concept of mixsets is introduced in Umple as a conditional unit and a first-class entity to allow smoothly transitioning software to compositional SPLs. A mixset is a named set of mixins; each mixin belonging to the mixset is called a fragment. A mixset fragment can be a top-level entity that contains nested entities or can be embedded as a conditional fragment in other entities such as methods. Mixset content normally includes code blocks or statements of any type, and may include require statements, which describe explicit dependencies among mixsets. Mixsets can be used to specify product lines using code composition, code annotation or both. A strength of mixsets lies on the straightforward mechanism to transform annotated segments into compositional segments when used in a combined approach. Therefore, preplanning effort and time to transform annotative SPLs to compositional SPLs can be reduced. Mixsets can provide a backbone structure to realize product line features in a feature-based SPL. Hence, a feature model can be formed using a subset of specific dependent mixsets. Feature interactions within an SPL can be identified and separated in specific modules by mixset nesting. Furthermore, product configuration, feature modeling analysis and generation of feature diagrams can be accomplished based on mixsets. The thesis also demonstrates a method to enable the granularity of compositional approaches to be expressed at the statement level. This is achieved by allowing aspects to inject code into labelled places, or points of variation, within method code. Such injected code has a full access to the context in which its placed, such as access to local variables. Mixsets are implemented in Umple, a model-driven development (MDD) technology that allows combining abstract models, such as associations and state machines, with pure code, and generating code in multiple programming languages. Mixsets can thus be used to describe variations in models, not just code. The thesis uses a design science approach as its research methodology. The mixset concept is evaluated through three case studies. The first applies mixsets to the Oracle Berkeley Database SPL, which is used in other literature to evaluate SPL concepts. This study shows that the mixset implementation improves on the state of the art in several respects, such as elimination of complex workarounds that are required by other approaches. In the second study, mixsets help to refactor Umple into feature-oriented SPL. The case study shows how annotative fragments can be easily transformed into compositional counterparts. In the third study, mixsets help to present two alternative solutions the to the Rover Control Challenge Problem of the MDETools 2018 workshop.

<p>The set of related products is referred to as a product family, and feature-modeling is a widely used technique to capture the commonalities and variabilities of a product family in terms of "features". With the growing complexity of software product families in several software industries, the development, maintenance and evolution of complex and large feature models are among the main challenges faced by feature-modeling practitioners. In particular, more sophisticated feature-modeling techniques are required to address the problems caused by unanticipated changes and crosscutting concerns in feature models.</p> <p>This thesis tackles the above challenges in feature-modeling by adopting the aspect-oriented paradigm at the feature-modeling level. I first introduce a specification language, called AO-PFA, which is an extension of the Product Family Algebra (PFA) language. I then proposed a formal verification technique to check the compatibility of aspects with their base specifications in AO-PFA. In the aspect-oriented paradigm, the process of combining aspects with base specifications is referred to as the weaving process. I finally discussed how to perform the weaving process in AO-PFA. By proposing a systematic approach to extend product family algebra with the abilities of specifying, verifying, and weaving aspects, we are able to handle the difficulties that arise from crosscutting concerns and unanticipated changes in large-scale feature models.</p> / Doctor of Philosophy (PhD)

Over the last decade, software has become an integral part of many products with which it is not traditionally associated (e.g., automobiles, medical equipment, home appliances, etc.). This has led to problems in many organizations, since it has proved difficult to integrate software engineering processes with other engineering processes. To address the increased complexity and to coordinate their engineering efforts, many organizations working in such domains have therefore introduced systems engineering into their business processes. Systems engineering is an interdisciplinary approach to system development. Teamwork is essential in developing complex systems, and systems engineering orchestrates this process throughout the lifespan of a system. The focus of systems engineering is on defining customer needs and required functionality, documenting requirements, synthesizing a design and validating the system. A problem with the traditional techniques of systems engineering is, however, that they provide inadequate support for achieving high levels of reuse between different projects. In this dissertation, methods and tools with the overall purpose of providing an improved reuse infrastructure for systems engineering artifacts and their resulting detailed design artifacts are proposed. The proposed methods and tools are based on the software product-line approach, a reuse strategy which focuses on families of related systems that address particular market segments. Studies have shown that if an empirical study does not report experiences from that which practitioners consider a “real” situation, results are likely to be ignored. Even though case studies cannot achieve the scientific rigor of formal experiments, case studies can provide enough information to decide if a specific technology will benefit a particular organization. To ensure industry-relevant research results, case studies on real development projects were chosen as the main vehicle for performing research. This dissertation reports experiences from four empirical studies which were performed within the Swedish defense industry. The studies indicate that the proposed methods and tools indeed provide an improved reuse infrastructure, compared to the previously used methods and tools.