Context: Requirements change commonly occurs during the software development lifecycle. Requirements traceability is one of the important techniques to support requirement change management and analysis, ensure quality and keep requirements consistent during development. We find that existing research mentioned various issues and challenges during practicing requirements traceability, and the practitioners show certain obstacles on the subject. Major existing work of the area focuses on requirements traceability processes, frameworks, and techniques to address certain issues accordingly. And we want to focus on and investigate the existing challenges to practice requirements traceability systematically. Method: We investigate the requirements traceability and its challenges through a systematic literature review (SLR) of various concepts and existing challenges of requirements traceability, and a survey of 7 Chinese small-and-medium-sized enterprises (SMEs). With 7 interviews, we studied different traceability practices and situations with the surveyed companies under the possible impact of requirement change, development processes, tools, and other factors. And then we conducted conventional qualitative content analysis to identify and classify the challenges in practicing requirements traceability. Results: With the systematic literature review, we classified 14 categories of academic identified challenges. Through the collected data of the survey, we identified and discussed 6 categories of the requirement traceability challenges, involving costs, tools, awareness, documentation, etc. And we compared and discussed the connections and differences of the survey results with the literature for validation of our survey results and possible extension to the existing work. Through research, we may help the practitioners to deal with requirements change with traceability practice better by recognizing and preventing the obstacles. Our research may provide researchers with more information on practical situations. And in the future, researchers may study the traceability models more effectively aiming at addressing the existing problems.

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Bibliography: leaves 223-247. Effects of water availability during grain filling is examined in wheat (Triticum aestivum L.) and barley (Hordum vulgare L.) genotypes. The study tests the accumulation of dry matter (DM) and nitrogen (N) in the grain and also their remobilization from the shoot to the grain. Water stress during grain filling was found to reduce DM and N accumulation and also to increase N concentration in both wheat and barley grain.

<p>This thesis reports on two studies in the field of multimedia. The older one, completed in 2002, has as a general aim to explore, describe and analyse the concept of multimedia in relation to the concept of information systems. Four areas are investigated: product, process, requirements work and knowledge exchange between developers of multimedia systems and developers of information systems. The main research question has been: What are the distinguishing features of multimedia and how can multimedia be characterised from an information systems perspective? The investigation has shown that multimedia development is characterized by co-operation between people from many different areas of expertise who respect each other’s knowledge. The development work requires creativity, rationality and a systematic approach Detailed explicit requirements specifications are seldom produced in the companies studied. Specifying requirements for multimedia products is complicated which seems to stem from the nature of multimedia which makes the products hard to describe using traditional means such as text.</p><p>A more recent study, completed in 2004, continues the investigation of the challenges concerning requirements specifications for multimedia products reported in the first study. For this purpose, a new methodology for experimenting with graphical user interfaces to obtain acceptable design solutions has been developed and tested. This methodology is based on an experimental technique called ‘Wizard of Oz’. In Wizard-of-Oz experiments a test person thinks he communicates with the computer in front of him when in actual fact the test manager sits in the next room interpreting the user’s commands and providing the desired responses. In order to use this technique for experimenting with graphical user interfaces a prototyping tool called Ozlab has been utilized. Ozlab has been used to allow doctors and nurses to participate in the design of a new user interface in a robot application for hip surgery. The results show that graphical Wizard-of-Oz prototyping can be a useful tool for exploration, visualization and communication of interaction requirements in multimedia product development.</p><p>The most recent study is placed first in this volume, followed by the older study (Karlstad University Studies 2002:24).</p>

Graduation date: 1994

This thesis reports on two studies in the field of multimedia. The older one, completed in 2002, has as a general aim to explore, describe and analyse the concept of multimedia in relation to the concept of information systems. Four areas are investigated: product, process, requirements work and knowledge exchange between developers of multimedia systems and developers of information systems. The main research question has been: What are the distinguishing features of multimedia and how can multimedia be characterised from an information systems perspective? The investigation has shown that multimedia development is characterized by co-operation between people from many different areas of expertise who respect each other’s knowledge. The development work requires creativity, rationality and a systematic approach Detailed explicit requirements specifications are seldom produced in the companies studied. Specifying requirements for multimedia products is complicated which seems to stem from the nature of multimedia which makes the products hard to describe using traditional means such as text. A more recent study, completed in 2004, continues the investigation of the challenges concerning requirements specifications for multimedia products reported in the first study. For this purpose, a new methodology for experimenting with graphical user interfaces to obtain acceptable design solutions has been developed and tested. This methodology is based on an experimental technique called ‘Wizard of Oz’. In Wizard-of-Oz experiments a test person thinks he communicates with the computer in front of him when in actual fact the test manager sits in the next room interpreting the user’s commands and providing the desired responses. In order to use this technique for experimenting with graphical user interfaces a prototyping tool called Ozlab has been utilized. Ozlab has been used to allow doctors and nurses to participate in the design of a new user interface in a robot application for hip surgery. The results show that graphical Wizard-of-Oz prototyping can be a useful tool for exploration, visualization and communication of interaction requirements in multimedia product development. The most recent study is placed first in this volume, followed by the older study (Karlstad University Studies 2002:24).

A software product line (SPL) succeeds because we exploit the similarities between a set of software-intensive systems, together with an understanding of their differences, to reduce development cost, maintenance cost, and user confusion. In SPL engineering, reuse is planned, enabled, and enforced. It is through the development of a set of core assets that reuse is systematically practiced. Requirements assets enhance the effectiveness of reuse since engineers can work on the abstractions closer to the systems' initial concepts. Contemporary SPL requirements engineerin (RE) approaches often adopt the proactive model to build a relatively complete and stable asset base. In practice, the substantial up-front effort and the abrupt transition from existing practices associated with the proactive model present a prohibitive SPL adoption barrier for many organizations that could otherwise benefit. The extractive model overcomes these shortcomings by reusing existing products for the SPL's initial baseline. In this thesis, we present a framework for applying lightweight techniques to extract, model, and analyze a SPL's requirements assets. We define the notion of functional requirements profiles (FRPs) according to the linguistic characterization of a domain's action-oriented concerns, and show that the FRPs can be extracted from a natural language document on the basis of domain-aware lexical affinities that bear a 'verb - direct object' relation. We model the extracted FRPs by analyzing their semantic cases and by extending the orthogonal variability model (OVM). We contribute a set of heuristic rules for uncovering the variation dimensions and dependencies, and discuss merging the OVMs extracted from multiple sources. We relate functional profiles to quality requirements via scenarios, and manage requirements interactions via concept analysis. We present two applications of FRPs to support some other activities in SPL engineering. We conduct several empirical studies to evaluate our framework. The results show that our approach allows the engineers to identify the domain elements more easily and develop the domain models more systematically. Our work fills the void with respect to extracting a SPL's requirements assets, and the main thrust of our work is to promote a set of lightweight, low adoption threshold techniques as a critical enabler for practitioners to capitalize on the order-of-magnitude improvements offered by SPL engineering.

Conceptual modeling allows abstraction, communication and consensus building in system development. It is challenging to expand and improve the accuracy of models in an iterative process, producing models able to facilitate analysis. Modeling and analysis can be especially challenging in early Requirements Engineering (RE), where high-level system requirements are discovered. In this stage, hard-to-measure non-functional requirements are critical; understanding the interactions between systems and stakeholders is a key to system success. Goal models have been introduced as a means to ensure stakeholder needs are met in early RE. Because of the high-level, social nature of early RE models, it is important to provide procedures which prompt stakeholder involvement (interaction) and model improvement (iteration). Most current approaches to goal model analysis require quantitative or formal information that is hard to gather in early RE, or produce analysis results automatically over models. Approaches are needed which balance automated analysis over complex models with the need for interaction and iteration. This work develops a framework for iterative, interactive analysis for early RE using agent-goal models. We survey existing approaches for goal model analysis, providing guidelines using domain characteristics to advise on procedure selection. We define requirements for an agent-goal model framework specific to early RE analysis, using these requirements to evaluate the appropriateness of existing work and to motivate and evaluate the components of our analysis framework. We provide a detailed review of forward satisfaction procedures, exploring how different model interpretations affect analysis results. A survey of agent-goal variations in practice is used to create a formal definition of the i* modeling framework which supports sensible syntax variations. This definition is used to precisely define analysis procedures and concepts throughout the work. The framework consists of analysis procedures, implemented in the OpenOME requirements modeling tool, which allow users to ask “What if?” and “Is this goal achievable, and how?” questions. Visualization techniques are introduced to aid analysis understanding. Consistency checks are defined over the interactive portion of the framework. Implementation, performance and potential optimizations are described. Group and individual case studies help to validate framework effectiveness in practice. Contributions are summarized in light of the requirements for early RE analysis. Finally, limitations and future work are described.

Conceptual modeling allows abstraction, communication and consensus building in system development. It is challenging to expand and improve the accuracy of models in an iterative process, producing models able to facilitate analysis. Modeling and analysis can be especially challenging in early Requirements Engineering (RE), where high-level system requirements are discovered. In this stage, hard-to-measure non-functional requirements are critical; understanding the interactions between systems and stakeholders is a key to system success. Goal models have been introduced as a means to ensure stakeholder needs are met in early RE. Because of the high-level, social nature of early RE models, it is important to provide procedures which prompt stakeholder involvement (interaction) and model improvement (iteration). Most current approaches to goal model analysis require quantitative or formal information that is hard to gather in early RE, or produce analysis results automatically over models. Approaches are needed which balance automated analysis over complex models with the need for interaction and iteration. This work develops a framework for iterative, interactive analysis for early RE using agent-goal models. We survey existing approaches for goal model analysis, providing guidelines using domain characteristics to advise on procedure selection. We define requirements for an agent-goal model framework specific to early RE analysis, using these requirements to evaluate the appropriateness of existing work and to motivate and evaluate the components of our analysis framework. We provide a detailed review of forward satisfaction procedures, exploring how different model interpretations affect analysis results. A survey of agent-goal variations in practice is used to create a formal definition of the i* modeling framework which supports sensible syntax variations. This definition is used to precisely define analysis procedures and concepts throughout the work. The framework consists of analysis procedures, implemented in the OpenOME requirements modeling tool, which allow users to ask “What if?” and “Is this goal achievable, and how?” questions. Visualization techniques are introduced to aid analysis understanding. Consistency checks are defined over the interactive portion of the framework. Implementation, performance and potential optimizations are described. Group and individual case studies help to validate framework effectiveness in practice. Contributions are summarized in light of the requirements for early RE analysis. Finally, limitations and future work are described.

A software product line (SPL) succeeds because we exploit the similarities between a set of software-intensive systems, together with an understanding of their differences, to reduce development cost, maintenance cost, and user confusion. In SPL engineering, reuse is planned, enabled, and enforced. It is through the development of a set of core assets that reuse is systematically practiced. Requirements assets enhance the effectiveness of reuse since engineers can work on the abstractions closer to the systems' initial concepts. Contemporary SPL requirements engineerin (RE) approaches often adopt the proactive model to build a relatively complete and stable asset base. In practice, the substantial up-front effort and the abrupt transition from existing practices associated with the proactive model present a prohibitive SPL adoption barrier for many organizations that could otherwise benefit. The extractive model overcomes these shortcomings by reusing existing products for the SPL's initial baseline. In this thesis, we present a framework for applying lightweight techniques to extract, model, and analyze a SPL's requirements assets. We define the notion of functional requirements profiles (FRPs) according to the linguistic characterization of a domain's action-oriented concerns, and show that the FRPs can be extracted from a natural language document on the basis of domain-aware lexical affinities that bear a 'verb - direct object' relation. We model the extracted FRPs by analyzing their semantic cases and by extending the orthogonal variability model (OVM). We contribute a set of heuristic rules for uncovering the variation dimensions and dependencies, and discuss merging the OVMs extracted from multiple sources. We relate functional profiles to quality requirements via scenarios, and manage requirements interactions via concept analysis. We present two applications of FRPs to support some other activities in SPL engineering. We conduct several empirical studies to evaluate our framework. The results show that our approach allows the engineers to identify the domain elements more easily and develop the domain models more systematically. Our work fills the void with respect to extracting a SPL's requirements assets, and the main thrust of our work is to promote a set of lightweight, low adoption threshold techniques as a critical enabler for practitioners to capitalize on the order-of-magnitude improvements offered by SPL engineering.