Showing papers presented at "IEEE International Conference on Requirements Engineering in 2007"

On Non-Functional Requirements

Abstract: Although the term 'non-functional requirement' has been in use for more than 20 years, there is still no consensus in the requirements engineering community what non-functional requirements are and how we should elicit, document, and validate them. On the other hand, there is a unanimous consensus that non-functional requirements are important and can be critical for the success of a project. This paper surveys the existing definitions of the term, highlights and discusses the problems with the current definitions, and contributes concepts for overcoming these problems.

Disambiguating the Documentation of Variability in Software Product Lines: A Separation of Concerns, Formalization and Automated Analysis

Abstract: Feature diagrams are a popular means for documenting variability in software product line engineering. When examining feature diagrams in the literature and from industry, we observed that the same modelling concepts are used for documenting two different kinds of variability: (1) product line variability, which reflects decisions of product management on how the systems that belong to the product line should vary, and (2) software variability, which reflects the ability of the reusable product line artefacts to be customized or configured. To disambiguate the documentation of variability, we follow previous suggestions to relate orthogonal variability models (OVMs) to feature diagrams. This paper reuses an existing formalization of feature diagrams, but introduces a formalization of OVMs. Then, the relationships between the two kinds of models are formalized as well. Besides a precise definition of the languages and the links, the important benefit of this formalization is that it serves as a foundation for a tool supporting automated reasoning on variability. This tool can, e.g., analyse whether the product line artefacts are flexible enough to build all the systems that should belong to the product line.

Addressing Legal Requirements in Requirements Engineering

Abstract: Legal texts, such as regulations and legislation, are playing an increasingly important role in requirements engineering and system development. Monitoring systems for requirements and policy compliance has been recognized in the requirements engineering community as a key area for research. Similarly, regulatory compliance is critical in systems that are governed by regulations and law, especially given that non-compliance can result in both financial and criminal penalties. Working with legal texts can be very challenging, however, because they contain numerous ambiguities, cross-references, domain-specific definitions, and acronyms, and are frequently amended via new regulations and case law. Requirements engineers and compliance auditors must be able to identify relevant regulations, extract requirements and other key concepts, and monitor compliance throughout the software lifecycle. This paper surveys research efforts over the past 50 years in handling legal texts for systems development. These efforts include the use of symbolic logic, logic programming, first-order temporal logic, deontic logic, defeasible logic, goal modeling, and semi-structured representations. This survey can aid requirements engineers and auditors to better specify, monitor, and test software systems for compliance.

How Does Requirements Quality Relate to Project Success or Failure

Abstract: Our research goal is to Jind relations between requirements quality and project success. To attain the goal, we investigated 32 projects started and completed during the period of 2003-2005 in a large business application software development division of a company in Tokyo. Data of requirements specijication quality evaluated by software quality assurance teams as well as overall project pevormance data in terms of cost and time overrun were available. Requirements specijication quality data were Jirst converted into a multiple-dimensional space, each dimension corresponding to an item of the recommended structure of software requirements specijications (SRS) deJined in IEEE Std. 830-1998. We applied various statistical analysis techniques over the SRS quality data and project outcomes. Some interesting relations between requirements quality and project success or failure were found, including: 1) a relatively small set of SRS items have strong impact on project success or failure; 2) descriptions of SRS in normal projects tend to be balanced; 3) SRS descriptions in Section 1, where purpose, overview and general context of SRS are written, are rich in normal projects and poor in overrun projects; 4) when the descriptions of SRS Section 1 are poor while those of functions and product perspective are rich, the project tends to result in a cost overrun.

Collaboration Patterns and the Impact of Distance on Awareness in Requirements-Centred Social Networks

Abstract: Because of intense collaborative needs, requirements engineering is a challenge in global software development. How do distributed teams manage the development of requirements in environments that require significant cross-site collaboration and coordination? In this paper, we report research that used social network analysis to explore collaboration and awareness among team members during requirements management in an industrial distributed software team. Using the lens of a requirements-centred social network to group team members who work on a particular requirement, we collected data to characterize requirements-centric collaborations in a project, and to examine aspects of awareness of requirements changes within these networks. Our findings indicate organic patterns of collaboration involving considerable cross-site interaction, in which communication of changes was the most predominant reason for interaction. Although we did not find evidence that distance affects developers' awareness of remote team members who work on the same requirements, distance affected how accessible the remote colleagues were. We discuss implications for knowledge sharing and coordination of work on a requirement in distributed teams, and propose directions for the design of collaboration tools that support awareness in distributed requirements management.

Specifying Monitoring and Switching Problems in Context

Abstract: Context-aware applications monitor changes in their operating environment and switch their behaviour to keep satisfying their requirements. Therefore, they must be equipped with the capability to detect variations in their operating context and to switch behaviour in response to such variations. However, specifying monitoring and switching in such applications can be difficult due to their dependence on varying contextual properties which need to be made explicit. In this paper, we present a problem- oriented approach to represent and reason about contextual variability and assess its impact on requirements; to elicit and specif' concerns facing monitors and switchers, such as initialisation and interference; and to specify monitoring and switching behaviours that can detect changes and adapt in response. We illustrate our approach by applying it to a published case study.

Consistency Checking of Conceptual Models via Model Merging

Abstract: Requirements elicitation involves the construction of large sets of conceptual models. An important step in the analysis of these models is checking their consistency. Existing research largely focuses on checking consistency of individual models and of relationships between pairs of models. However, such strategy does not guarantee global consistency. In this paper, we propose a consistency checking approach that addresses this problem for homogeneous models. Given a set of models and a set of relationships between them, our approach works by first constructing a merged model and then verifying this model against the consistency constraints of interest. By keeping proper traceability information, consistency diagnostics obtained over the merge are projected back to the original models and their relationships. The paper also presents a set of reusable expressions for defining consistency constraints in conceptual modelling. We demonstrate the use of the developed expressions in the specification of consistency rules for class and ER diagrams, and i* goal models.

Requirements in the wild: How small companies do it

Abstract: Small companies form a large part of the software industry, but have mostly been overlooked by the requirements engineering research community. We know very little about the techniques these companies use to elicit and track requirements and about their contexts of operations. This paper presents preliminary results from an ongoing exploratory case study of requirements management in seven small companies, which found that (a) successful small companies exhibit a huge diversity of requirements practices that work well enough for their contexts; (b) these companies display strong cultural cohesion; (c) the principal of the company tends to retain control of the requirements processes long after other tasks have been delegated; and (d) the evidence rejects the simplistic view of a current "software crisis", as requirements errors for these companies, though problematic, are rarely catastrophic. We develop a number of hypotheses to explain these findings.

Towards Automated Requirements Triage

Abstract: Budgetary restrictions and time-to-market deadlines often require stakeholders to prioritize requirements and decide which ones to include in a given product release. Lack of an effective prioritization and triage process can lead to problems such as missed deadlines, disorganized development efforts, and late discovery of architecturally significant requirements. 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 proposes an approach for automating a significant part of the prioritization process. The proposed method utilizes a probabilistic traceability model combined with a standard hierarchical clustering algorithm to cluster incoming stakeholder requests into hierarchical feature sets. Additional cross-cutting clusters are then generated to represent factors such as architecturally significant requirements or impacted business goals. Prioritization decisions are initially made at the feature level and then more critical requirements are promoted according to their relationships with the identified cross-cutting concerns. The approach is illustrated and evaluated through a case study applied to the requirements of the ice breaker system.

Persona-Scenario-Goal Methodology for User-Centered Requirements Engineering

Abstract: This paper proposes Persona-Scenario-Goal (PSG) methodology as an extension of Persona-Scenario methodology, and its empirical study in the usercentered requirements engineering for a Web application system. The Persona-Scenario methodology demonstrated the effectiveness in capturing requirements of consumer products, such as mobile phones. However, the methodology has limitations to evaluate the multiple, possibly conflicting, requirements. The PSG methodology intended to identify a set of value requirements from multiple and even conflicting requirements by combining persona, scenario and goal-oriented techniques. This paper discusses the model and procedure of PSG methodology, and demonstrates its effectiveness by applying the methodology to reengineering a Web application system.

Scenarios: Identifying Missing Objects and Actions by Means of Computational Linguistics

Abstract: In industrial requirements documents natural language is the main presentation means. In such documents, system behavior is specified in the form of scenarios, written as a sequence of sentences in natural language. The scenarios are often incomplete: For the authors of requirements documents some facts are so obvious that they forget to mention them. This surely causes problems for the requirements analyst. This paper presents an approach that analyzes textual scenarios with the means of computational linguistics, identifies where communicating objects or whole actions are missing in the text, completes the missing information, and creates a message sequence chart (MSC) including the information missing in the textual scenario. Finally, this MSC is presented to the requirements analyst for validation. The paper presents also a case study in which scenarios from a requirement document based on industrial specifications were translated to MSCs. The case study shows the feasibility of the approach.

Business Process-Based Regulation Compliance: The Case of the Sarbanes-Oxley Act

Abstract: Balance Sheets and Annual Financial Reports play a major role in determining the public worth of any company. In the wake of corporate scandals such as Enron and WorldCom, the US and other countries passed legislation governing reporting processes. The Sarbanes Oxley Act of 2002 (hereafter SOX) requires US national securities exchange and US national security associations not to list any securities of any issuer that is not in compliance with the act. In this paper, we present a business process-based solution to the SOX compliance problem and offer evidence that such a solution is feasible through an industrial case study. The proposed solution aims to support SOX reporting requirements based on core business processes and a continuous improvement of the company's adopted business processes. This means that the solution integrates SOX-related tasks into the "daily work" of a company, rather than achieve compliance on a project basis.

Value-Based Requirements Traceability: Lessons Learned

Abstract: Software development standards demand requirements traceability without being explicit about the appropriate level of quality of trace links. Unfortunately, long-term trace utilizations are typically unknown at the time of trace acquisition which represents a dilemma for many companies. This paper suggests ways to balance the cost and benefits of requirements traceability. We present data from 3 case studies. Lessons learned suggest a traceability strategy that (1) provides trace links more quickly, (2) refines trace links according to user-definable value considerations, and (3) supports the later refinement of trace links in case the initial value considerations change.

Industry Survey of Product Lines Management Tools: Requirements, Qualities and Open Issues

Abstract: PLM approaches are becoming a prominent approach in the Software Engineering and Systems Engineering PL contexts. The idea behind PLM is to focus on artifacts that are shared and that vary from one product to the other, so as to facilitate reuse and adaptation. Gains are expected in terms of time to market, consistency across products, easier identification of requirements for future products, costs reduction, better flexibility, and better management of change requirements. While most of the recent research works are focusing on methods and modeling techniques, little has been done so far with respect to PLM tools and their ability to answer industry needs. A study was thus undertaken in collaboration with a group of industrials to evaluate existing PLM tools. The purpose of the study was twofold: to understand the salient characteristics of PLM tools, and to evaluate the ability of existing tools to satisfy the expectations of industrials. The study was conducted using (a) a state of the art of PLM methods, (b) an analysis grid developed by the industrial partners to analyze the characteristics ofPM tools in general, and (c) interviews with our industrial partners. This paper reports our analysis under the form of a benchmark aimed at being used by industrials to select existing tools, and discusses open issues in the domain of RE for PL.

Technique Integration for Requirements Assessment

Abstract: In determining whether to permit a safety-critical software system to be certified and in performing independent verification and validation (IV&V) of safety- or mission-critical systems, the requirements traceability matrix (RTM) delivered by the developer must be assessed for accuracy. The current state of the practice is to perform this work manually, or with the help of general-purpose tools such as word processors and spreadsheets Such work is error-prone and person-power intensive. In this paper, we extend our prior work in application of Information Retrieval (IR) methods for candidate link generation to the problem of RTM accuracy assessment. We build voting committees from five IR methods, and use a variety of voting schemes to accept or reject links from given candidate RTMs. We report on the results of two experiments. In the first experiment, we used 25 candidate RTMs built by human analysts for a small tracing task involving a portion of a NASA scientific instrument specification. In the second experiment, we randomly seeded faults in the RTM for the entire specification. Results of the experiments are presented.

Early Requirements and Business-IT Alignment with SEAM for Business

Abstract: The early requirements of an IT system should be aligned with the organization's business imperatives. To understand these imperatives it is necessary to understand the organization's position within its environment. SEAM for Business is a method designed for analyzing the competitive environment of an organization, including its relationships with its customers, partners, and market regulators. From this analysis, the main requirements of the IT systems can be inferred. We illustrate the use of SEAM for Business with a real project aimed at redesigning the website of a consulting company.

Exploring Business Process Transparency Concepts

Abstract: Transparency has been, for long, a general requirement for democratic societies. According to Leite [6], transparency will be a central issue in producing software. This work assumes that, for providing software transparency, it is necessary that the processes to be supported or automated be transparent as well. As such, using a requirements point of view, it is necessary that organizations implement process transparency to enable transparency in their automation or support. This work is based on Business Process Management concepts, NFR framework and quality management.

COSMOD-RE: Supporting the Co-Design of Requirements and Architectural Artifacts

Abstract: The need for co-designing requirements and architecture for innovative software-intensive systems is widely accepted. In this paper, we present the key ideas of our method COSMOD-RE for supporting the co-design of requirements and architectural artifacts. The backbone of COSMOD-RE is a hierarchy of four abstraction layers. At each layer, a requirements viewpoint and an architectural viewpoint are co-developed and aligned using a goal- and scenario-based approach. COSMOD-RE defines three co-design processes and five sub-processes for each co-design process to structure and guide the co-development.

Challenges in Requirements Engineering for Mobile Games Development: The Meantime Case Study

Abstract: The development of new market-driven software products involves several challenges for the requirements engineering process. The challenges are deeper in the case these products are mobile video games. In particular, the mobile games must satisfy a number of critical non-functional requirements (e.g. portability, gameplay, emotional issues). In addition to that, mobile games are developed for mass market, demanding from the development team to understand the requirements of very diverse and sometimes unknown groups of stakeholders. This paper presents the experience of meantime, a global mobile game developing company, in conducting requirements engineering activities during the development of the Frogman game. It also presents some lessons learned in the process.

Requirements Engineering as a Driver for Innovations

Abstract: Under today's fiercely competitive conditions, companies are seeking new means to develop innovative products that satisfy customer and user needs. In order to understand how requirements engineering (RE) can support innovations, we observed RE activities in six Finnish companies. Our observations indicate that RE can play a vital role in the development of innovative products. We identified three main opportunities for innovations: 1) discovering hidden customer and user needs, 2) inventing new product features that satisfy these needs, and 3) supporting feature development with an innovative technical solution. Based on our observations, as well as on existing innovation and business-management literature, we have concluded that RE research can gain significant results by investigating how to discover and model hidden customer and user needs. We believe that this would allow RE to much better support those innovation practices that provide real competitive advantage.

Evolution in Product Line Requirements Engineering: A Rationale Management Approach

Abstract: Product line evolution is one of the burning issues in product line requirements engineering. It is more complicated than single system requirements engineering because of the conflicting requirements across the product lines, the effect of evolution on the reuse and customization, and the global distribution of product line organizations. As product lines are long-term investments, handling their evolution is critical. This paper proposes a new technique called rationale-based product line evolution. It is based on the Questions, Options and Criteria model and a modified version of EasyWinWin. The technique allows the evaluation of change requests in product line requirements based on the informal collaboration of stakeholders, capturing the forces that cause evolution and using them for the justification of change requests. The technique has been implemented in the Sysiphus tool and was validated using empirical evaluation.

Built-in User Satisfaction - Feature Appraisal and Prioritization with AMUSE

Abstract: In today's world, the users of software-based products demand a lot. They want the systems to offer the needed functionality, show high performance and, at the same time, be usable and trustworthy. Especially consumer products should also offer joy to the user. The success of a software-based product strongly depends on how well the product fulfills these user expectations. Therefore, considering the users' expectations should be an integral part of modern system engineering activities. This paper shows an approach that was designed to appraise and measure the users' (future) satisfaction in an early phase of system development: the requirements engineering phase. In this phase little systematic guidance exists on how to evaluate the effects of features on user satisfaction early on, and on how to contribute the results to the development process. AMUSE (appraisal and measurement of user satisfaction), the approach presented in this paper, closes this gap. It helps requirements engineers and product managers to select the most promising features, i.e., the ones that will satisfy the user the most, already in the requirements phase. The approach uses a standardized user satisfaction measurement device (questionnaire), a feature appraisal and prioritization methodology, and tool support. This approach was developed and piloted in cooperation with Siemens AG, Germany.

Using Satisfaction Arguments to Enhance i* Modelling of an Air Traffic Management System

Abstract: This paper reports the integration of satisfaction arguments into i* goal modelling to support analyses of the impact of new software systems on system-wide goals. Integration is based on a conceptual model that relates satisfaction argument and i* model concepts. New impact analysis procedures based on the integrated models and satisfaction arguments are introduced.

Embedded Knowledge and Offshore Software Development

Abstract: Offshore software development scenarios may include groups with domain specific knowledge who collaborate internationally across multiple local contexts. In this paper we develop a conceptual scheme based on theories associated with embedded knowledge. Drawing on evidence from case studies of software companies with offshore subsidiaries in India and other locations, we discuss problems associated with the embeddedness of knowledge in geographically-separated units of a firm. We provide some practical implications for managing embedded knowledge in offshore software development. Dr Brian Nicholson is a Senior Lecturer at Manchester Business School. For the last 11 years, he has been involved in teaching, research and consultancy projects in the broad area of managing global outsourcing of software and other business processes. This has involved work in India, China, Costa Rica, Iran, Egypt; Malaysia and Bangladesh. Dr Nicholson's research at the firm level has resulted in several influential publications in international journals and a book Global IT Outsourcing (Cambridge University Press, 2003). Policy level consultancy studies have been undertaken for the governments of Costa Rica and Iran to stimulate software exports. In the case of Costa Rica, this resulted in production of a national level strategy. His most recent work has been commissioned by the Institute of Chartered Accountants in England and Wales: “Risk and Control of Offshore Outsourcing of Accounting Services.”

Goal-Oriented Conceptual Database Design

Abstract: We present details of a goal-oriented process for database requirements analysis. This process consists of a number of steps, spanning the spectrum from high-level stakeholder goal analysis to detailed conceptual schema design. The paper shows how goal modeling contributes to systematic scoping and analysis of the application domain, and subsequent formal specification of database requirements based on this domain analysis. Moreover, a goal-oriented design strategy is proposed to structure the transformation from the domain model to the conceptual schema, according to a set of user defined design issues, also modeled as goals. The proposed process is illustrated step-by-step using a running example from the design of a real-world, industrial biological database. We also report early progress towards building full tool support, by presenting a prototype that captures and stores design sessions in a queryable form. This facility makes it possible to answer questions that are hard, if not impossible, to answer using existing methodologies for database design.

Secure and dependable patterns in organizations: an empirical approach

Abstract: Designing a secure and dependable system is not just a technical issue, it involves also a deep analysis of the organizational and the social environment in which the system will operate. In this paper, we detail our experience in modeling and analyzing requirements for an industrial case (air traffic management system) using the Secure Tropos framework. Particularly, we focus on modeling and reasoning about trust and risk relations within the organizational structure; we discuss pros and cons of Secure Tropos stemming from our experience and lessons learned which might be general interests for RE methodologies.

Strengthening the link between business decisions and RE: Long-term product planning in software product companies

Abstract: Long-term product planning (i.e. roadmapping) is an approach that companies operating in the software product business have used to bridge the gap between business planning and product development. A strong link between strategy and product development is important, since companies developing software products need to select requirements for forthcoming releases based on the business decisions of the company. However, in practice, connecting requirements engineering decisions and business management is far from trivial. This paper reports lessons learned from four software product companies that recognize the need for more business-oriented long- term product planning. The study was conducted using the action research approach. We identified four practices that seem to strengthen the link between business decisions and requirements engineering. These are: 1) explicating the planning levels and time horizons needed in product planning, 2) separating the planning of business goals relating to products from R&D resource allocation, 3) conducting open-ended planning by pre-defined rhythm and 4) emphasizing whole-product thinking.

Tracing and Validating Goal Aspects

Abstract: Aspects promote a clear separation of concerns so that tangled and scattered concerns are modularized throughout software development. We propose a framework to trace aspects identified during goal-oriented requirements analysis to code and testing. Two types of checks are performed to validate the resulting system in light of stakeholders' cross- cutting concerns. One ensures that systems with and without aspects have the same functionality defined by the hard goals. The other checks whether the weaved system with aspects indeed improves system qualities in terms of the degree of softgoal satisfaction. We demonstrate the approach using an open-source e-commerce platform.

Using a Game to Introduce Lightweight Requirements Engineering

Abstract: This paper describes a game that is being designed to introduce basic Requirements Engineering good practices into a novice organization. Since this is work in progress, we will demonstrate a functional version of the game during the session and seek participation in game-play to inform our early concept exploration.

The Mobile Scenario Presenter: A Tool for in situ Requirements Discovery with Scenarios

Abstract: Scenarios are widely and successfully used to discover requirements for software-intensive systems. Recent advances in mobile computing technologies mean that mobile tools can support scenario-based techniques in the workplace, with potential benefits to requirements processes. To explore this idea we have been developing the Mobile Scenario Presenter (MSP) tool and used it successfully in a number of evaluation studies and projects. The MSP supports analysts working in the field to better understand the work context of a future system 's end users. The interactive tool demo allows RE experts to actively use the MSP to explore its capabilities and benefits.