A requirements capture method and its use in an air traffic control application

This paper describes our experience in capturing, using a formal specification language, a model of the knowledge-intensive domain of oceanic air traffic control. This model is intended to form part of the requirements specification for a decision support system for air traffic controllers. We give an overview of the methods we used in analysing the scope of the domain, choosing an appropriate formalism, developing a domain model, and validating the model in various ways. Central to the method was the development of a formal requirements engineering environment which provided automated tools for model validation and maintenance.     

An approach for high-yield requirements capture for e-commerce and its application

Web-based e-commerce software is typically real-time, responsive, and distributed software that must meet high quality requirements. Moreover, because of its Internet-based operating environment, e-commerce software must deal with concurrency, synchronization, and non-deterministic issues (such as delays) primarily caused by the heavy usage load and underlying network conditions. In this paper, we introduce a generic, cost-effective approach to optimize requirements capture (and subsequent development and testing) with respect to functional coverage and customer perception of quality. This high-yield approach is presented and illustrated by application to an e-commerce online shopping system and used to explain the principles of use-case requirements captured in the unified modeling language. Published online: 25 July 2001     

Static analysis of Lyee requirements

Software development has been suffering, for many decades, from the lack of simple and powerful methodologies and tools. Despite the tremendous advances in this research field, the crisis has still not been overcome and the proposed remedies are far from resolving the problems of software development and maintenance. Lately, a new and very promising methodology, called Lyee, has been proposed. It aims to automatically generate programs from simple user requirements.

The purpose of this paper is, on the one hand, to provide a short and technical introduction to the Lyee methodology, and on the other hand, to show how some classical static analysis techniques (execution time and memory space optimization, typing, slicing, etc.) can considerably improve many aspects of this new methodology.     

Scenario-based requirements capture for human factors integration

Scenarios have been used by many engineering disciplines to assist the quality of their professional application to systems throughout a system life-cycle. At early phases of the system life-cycle, Systems and Software Engineers have adopted the Use Case as a means of representing system requirements through the address of user functions. Furthermore, usability engineers also use scenarios as a means of promoting better usability of systems throughout the system life-cycle. Moreover, all practitioners of the mentioned disciplines use some form of requirements capture and trace throughout the system life-cycle. However, in general Human Factors (HF) and Human Factors Integration (HFI) practitioners do not. This paper examines the efficacy of the multi disciplinary use of scenarios to assist the capture of HFI and system requirements. Such an approach benefits the early establishment of requirements and thus supports system life-cycle trace and matching of both physical and cognitive functions. Any views expressed are those of the author(s) and do not necessarily represent those of MOD or any other UK government department.     

User viewpoint modelling: understanding and representing user viewpoints during requirements definition

There has been increasing awareness of the impact of the early stages of systems development on the quality of information systems. A critical early activity is requirements definition, when the requirements for an information system are determined. Traditional requirements capture techniques do not support the collaborative nature of requirements definition or the emergent nature of requirements themselves. This paper focuses on viewpoint development as a means of resolving some of the difficulties of requirements definition. It proposes a user viewpoint model for capturing and representing the viewpoints of users during requirements acquisition. The model can facilitate communication and interaction between analysts and users and help build a shared understanding of requirements. It can be used to structure the requirements acquisition process. The model provides for evaluation of requirements acquisition techniques to guide the selection of appropriate techniques for developing user viewpoint models. The paper reports a multiple-case study of requirements definition efforts that examined user viewpoint development in practice and used the cases to validate empirically the concepts of the user viewpoint model. The implications of the case study findings for requirements definition practice are discussed, and some areas for future research are identified.     

Adapting to changing user requirements

Systems which have the capability of adapting to changing user requirements must be founded on accurate and perceptive models of the organisation in which they have to function. Design methods based on active user participation and the use of experimental and prototyping methods help to ensure accurate models. But because systems are expected to survive even when circumstances change, the designers have to have a view of what the future world will look like. A technique which helps to provide such a view is called “future analysis”. However, even designs based on the best prediction technique cannot guarantee a fit between the currently designed system and future needs. Hence it is important to design systems with built-in flexibility. A number of methods have been developed which reduce the disruption caused by the amendment or even replacement of a system or system's component.     

The impacts of user review on software responsiveness: Moderating requirements uncertainty

Rapidly changing business environments and evolving processes increase the uncertainties in IS development. To produce a high-quality system that responds to user needs is challenging. We attempted to determine whether user reviews during the development process could reduce uncertainties and improve the product. Technology structuration theory indicated that users, as actors participating in reviews during the development of a system, could help reduce uncertainty in the organizational requirements and thus improve the software product. A survey of system developers indicated that user requirements uncertainty had a direct, negative effect on software responsiveness but that user review, serving as a moderator, could reduce this effect.     

Evaluating requirements modeling methods based on user perceptions: A family of experiments

Numerous methods and techniques have been proposed for requirements modeling, although very few have had widespread use in practice. One drawback of requirements modeling methods is that they lack proper empirical evaluations. This means that there is a need for evaluation methods that consider both the theoretical and practical aspects of this type of methods and techniques. In this paper, we present a method for evaluating the quality of requirements modeling methods based on user perceptions. The evaluation method consists of a theoretical model that explains the relevant dimensions of quality for requirements modeling methods, along with a practical instrument with which to measure these quality dimensions. Basically, it allows us to predict the acceptance of a particular requirements modeling method in practice, based on the effort of applying the method, the quality of the requirements artifacts produced, and the user perceptions with regard to the quality of the method. The paper also presents an empirical test of the proposed method for evaluating a Rational Unified Process (RUP) extension for requirements modeling. That test was carried out through a family of experiments conducted with students and practitioners and provides evidence of the usefulness of the evaluation method proposed.     

Animation of requirements specifications

Requirements analysis has been recognized as one of the most critical and difficult tasks in software engineering. The need for tool support is essential. This paper reports some work done to provide such support for interpretation and validation of requirements specifications by animation. The Animator provides facilities for the selection and execution of a transaction to reflect the specified behaviour of a particular scenario specified in the requirements specification. Actions are described in terms of input-output mappings and or functions with pattern matching. Simple rules can be specified to control the triggering of actions. In addition, facilities are provided to replay and interact with transactions. User interaction during animation includes the ability to change data values or role play selected actions as desired. A full graphical interface is supported. The approach has been tested by the provision of an Animator for the requirements analysis method CORE and an associated ‘Analyst Workstation’. Animation has been tested on a number of small examples and a major case study. This paper describes the Animator, justifies the approach taken and discusses experience and future work.     

Using classification techniques for informal requirements in the requirements analysis-supporting system

In order to efficiently develop large-scale and complicated software, it is important for system engineers to correctly understand users’ requirements. Most requirements in large-scale projects are collected from various stakeholders located in various regions, and they are generally written in natural language. Therefore, the initial collected requirements must be classified into various topics prior to analysis phases in order to be usable as input in several requirements analysis methods. If this classification process is manually done by analysts, it becomes a time-consuming task. To solve this problem, we propose a new bootstrapping method which can automatically classify requirements sentences into each topic category using only topic words as the representative of the analysts’ views. The proposed method is verified through experiments using two requirements data sets: one written in English and the other in Korean. The significant performances were achieved in the experiments: the 84.28 and 87.91 F1 scores for the English and Korean data sets, respectively. As a result, the proposed method can provide an effective function for an Internet-based requirements analysis-supporting system so as to efficiently gather and analyze requirements from various and distributed stakeholders by using the Internet.     

Identified adjustability dimensions when generating a product specific requirements specification by requirements reuse

A requirements reuse setups typically includes reusable requirement set(s) containing a collection of reusable requirements and a number of product specific requirements sets which are drawn from the reusable set(s). The ideal scenario when reusing requirements is that all the product requirements can be drawn directly from the reusable set. However, this is rarely the case in product development as new requirements are likely to surface. A critical issue in requirements reuse therefore becomes how to enable products to efficiently reuse requirements as well incorporating changes to the product set. In this paper the objective is not to present a specific method for requirements reuse but to introduce and discuss the possible dimensions of adjustability when generating a product requirement set by reusing requirements from a reusable set. Six adjustability dimensions have been identified. An extensive state of the art is included to introduce the presented methods related to each adjustability dimensions. The options for implementing each adjustability dimensions in a requirement reuse approach are illustrated along with a discussion regarding the benefits and issues resulting from each option. This discussion should help practitioners to better understand the possible methods that can be implemented and to design a user friendly and sustainable approach. A case study, describing how the dimensions are incorporated in two requirements reuse approaches, for Danfoss Solar Inverters (SI) and Danfoss Frequency Drives is provided. As a result an overview of how each adjustability dimensions is implemented in each case is presented. The case study demonstrates that all the identified adjustability dimensions were important elements in requirements reuse implementation. The case study furthermore highlights the need, not only to understand the effects of each adjustability dimension but also of the dependencies to case specific criterions. The classification of adjustability dimensions in requirements reuse and the options for their implementation has not been outlined by previous research and should be a useful contribution both to researchers and practitioners working in the field of requirements reuse.     

Improved practical support for large-scale requirements prioritising

An efficient, accurate and practical process for prioritising requirements is of great importance in commercial software developments. This article improves an existing cost-value approach in which stakeholders compare all unique pairs of candidate requirements according to their value and their cost of implementation. Techniques for reducing the required number of comparisons are suggested, thus making the process more efficient. An initial approach for managing requirements interdependencies is proposed. A support tool for the improved process has been developed to make the process more practical in commercial developments. The improved process and its support tool have been applied and evaluated in an industrial project at Ericsson Radio Systems AB. The results indicate a pressing need for mature processes for prioritising requirements, and the work presented here is an important step in that direction.     

Improving the detection of requirements discordances among stakeholders

This paper introduces a technique to identify requirements discordances among stakeholders. This technique is validated in experiments. An extended version of the goal-oriented requirements elicitation method, named attributed goal-oriented analysis (AGORA), and its supporting tool are used. Two types of requirements discordances among stakeholders are defined: the first arises from the different interpretations by the stakeholders and the second is the result of different evaluations of preferences. Discordances are detected by the preference matrices in AGORA. Each preference matrix represents both preferences of each stakeholder and the estimated preferences of other stakeholders. A supporting tool for the AGORA method was developed. This tool is a groupware that seamlessly combines face-to-face meetings for goal elicitation and distributed individual sessions for scoring preference values. The experimental results showed that the proposed classification of discordances was sound and that the occurrences of the requirements discordances could be detected by preference matrices.     

The state of the art in automated requirements elicitation

ContextIn large software development projects a huge number of unstructured text documents from various stakeholders becomes available and needs to be analyzed and transformed into structured requirements. This elicitation process is known to be time-consuming and error-prone when performed manually by a requirements engineer. Consequently, substantial research has been done to automate the process through a plethora of tools and technologies.ObjectiveThis paper aims to capture the current state of automated requirements elicitation and derive future research directions by identifying gaps in the existing body of knowledge and through relating existing works to each other. More specifically, we are investigating the following research question: What is the state of the art in research covering tool support for automated requirements elicitation from natural language documents?MethodA systematic review of the literature in automated requirements elicitation is performed. Identified works are categorized using an analysis framework comprising tool categories, technological concepts and evaluation approaches. Furthermore, the identified papers are related to each other through citation analysis to trace the development of the research field.ResultsWe identified, categorized and related 36 relevant publications. Summarizing the observations we made, we propose future research to (1) investigate alternative elicitation paradigms going beyond a pure automation approach (2) compare the effects of different types of knowledge on elicitation results (3) apply comparative evaluation methods and multi-dimensional evaluation measures and (4) strive for a closer integration of research activities across the sub-fields of automatic requirements elicitation.ConclusionThrough the results of our paper, we intend to contribute to the Requirements Engineering body of knowledge by (1) conceptualizing an analysis framework for works in the area of automated requirements elicitation, going beyond former classifications (2) providing an extensive overview and categorization of existing works in this area (3) formulating concise directions for future research.     

User requirements of mobile technology: results from a content analysis of user reviews

Advanced mobile technology continues to shape professional environments. Smart cell phones, pocket computers and laptop computers reduce the need of users to remain close to a wired information system infrastructure and allow for task performance in many different contexts. Among the consequences are changes in technology requirements, such as the need to limit weight and size of the devices. In the current paper, we focus on the factors that users find important in mobile devices. Based on a content analysis of online user reviews that was followed by structural equation modeling, we found four factors to be significantly related with overall user evaluation, namely functionality, portability, performance, and usability. Besides the practical relevance for technology developers and managers, our research results contribute to the discussion about the extent to which previously established theories of technology adoption and use are applicable to mobile technology. We also discuss the methodological suitability of online user reviews for the assessment of user requirements, and the complementarity of automated and non-automated forms of content analysis.     

The brave new world of design requirements

Despite its success over the last 30 years, the field of Requirements Engineering (RE) is still experiencing fundamental problems that indicate a need for a change of focus to better ground its research on issues underpinning current practices. We posit that these practices have changed significantly in recent years. To this end we explore changes in software system operational environments, targets, and the process of RE. Our explorations include a field study, as well as two workshops that brought together experts from academia and industry. We recognize that these changes influence the nature of central RE research questions. We identify four new principles that underlie contemporary requirements processes, namely: (1) intertwining of requirements with implementation and organizational contexts, (2) dynamic evolution of requirements, (3) emergence of architectures as a critical stabilizing force, and (4) need to recognize unprecedented levels of design complexity. We recommend a re-focus of RE research based on a review and analysis of these four principles, and identify several theoretical and practical implications that flow from this analysis.     

Towards automated requirements prioritization and triage

Time-to-market deadlines and budgetary restrictions require stakeholders to carefully prioritize requirements and determine which ones to implement in a given product release. Unfortunately, existing prioritization techniques do not provide sufficient automation for large projects with hundreds of stakeholders and thousands of potentially conflicting requests and requirements. This paper therefore describes a new approach for automating a significant part of the prioritization process. The proposed method utilizes data-mining and machine learning techniques to prioritize requirements according to stakeholders’ interests, business goals, and cross-cutting concerns such as security or performance requirements. The effectiveness of the approach is illustrated and evaluated through two case studies based on the requirements of the Ice Breaker System, and also on a set of stakeholders’ raw feature requests mined from the discussion forum of an open source product named SugarCRM.