Agile Requirements Research Articles

A systematic literature review on quality criteria for agile requirements specifications

The quality of requirements is typically considered as an important factor for the quality of the end product. For traditional up-front requirements specifications, a number of standards have been defined on what constitutes good quality : Requirements should be complete, unambiguous, specific, time-bounded, consistent, etc. For agile requirements specifications, no new standards have been defined yet, and it is not clear yet whether traditional quality criteria still apply. To investigate what quality criteria for assessing the correctness of written agile requirements exist, we have conducted a systematic literature review. The review resulted in a list of 16 selected papers on this topic. These selected papers describe 28 different quality criteria for agile requirements specifications. We categorize and analyze these criteria and compare them with those from traditional requirements engineering. We discuss findings from the 16 papers in the form of recommendations for practitioners on quality assessment of agile requirements. At the same time, we indicate the open points in the form of a research agenda for researchers working on this topic .

Agile Requirements Engineering: A systematic literature review

Nowadays, Agile Software Development (ASD) is used to cope with increasing complexity in system development. Hybrid development models, with the integration of User-Centered Design (UCD), are applied with the aim to deliver competitive products with a suitable User Experience (UX). Therefore, stakeholder and user involvement during Requirements Engineering (RE) are essential in order to establish a collaborative environment with constant feedback loops. The aim of this study is to capture the current state of the art of the literature related to Agile RE with focus on stakeholder and user involvement. In particular, we investigate what approaches exist to involve stakeholder in the process, which methodologies are commonly used to present the user perspective and how requirements management is been carried out.We conduct a Systematic Literature Review (SLR) with an extensive quality assessment of the included studies. We identified 27 relevant papers. After analyzing them in detail, we derive deep insights to the following aspects of Agile RE: stakeholder and user involvement, data gathering, user perspective, integrated methodologies, shared understanding, artifacts, documentation and Non-Functional Requirements (NFR). Agile RE is a complex research field with cross-functional influences. This study will contribute to the software development body of knowledge by assessing the involvement of stakeholder and user in Agile RE, providing methodologies that make ASD more human-centric and giving an overview of requirements management in ASD.

A multi-case study of agile requirements engineering and the use of test cases as requirements

ContextIt is an enigma that agile projects can succeed ‘without requirements’ when weak requirements engineering is a known cause for project failures. While agile development projects often manage well without extensive requirements test cases are commonly viewed as requirements and detailed requirements are documented as test cases. ObjectiveWe have investigated this agile practice of using test cases as requirements to understand how test cases can support the main requirements activities, and how this practice varies. MethodWe performed an iterative case study at three companies and collected data through 14 interviews and two focus groups. ResultsThe use of test cases as requirements poses both benefits and challenges when eliciting, validating, verifying, and managing requirements, and when used as a documented agreement. We have identified five variants of the test-cases-as-requirements practice, namely de facto, behaviour-driven, story-test driven, stand-alone strict and stand-alone manual for which the application of the practice varies concerning the time frame of requirements documentation, the requirements format, the extent to which the test cases are a machine executable specification and the use of tools which provide specific support for the practice of using test cases as requirements. ConclusionsThe findings provide empirical insight into how agile development projects manage and communicate requirements. The identified variants of the practice of using test cases as requirements can be used to perform in-depth investigations into agile requirements engineering. Practitioners can use the provided recommendations as a guide in designing and improving their agile requirements practices based on project characteristics such as number of stakeholders and rate of change.

Improving agile requirements: the Quality User Story framework and tool

User stories are a widely adopted requirements notation in agile development. Yet, user stories are too often poorly written in practice and exhibit inherent quality defects. Triggered by this observation, we propose the Quality User Story (QUS) framework, a set of 13 quality criteria that user story writers should strive to conform to. Based on QUS, we present the Automatic Quality User Story Artisan (AQUSA) software tool. Relying on natural language processing (NLP) techniques, AQUSA detects quality defects and suggest possible remedies. We describe the architecture of AQUSA, its implementation, and we report on an evaluation that analyzes 1023 user stories obtained from 18 software companies. Our tool does not yet reach the ambitious 100 % recall that Daniel Berry and colleagues require NLP tools for RE to achieve. However, we obtain promising results and we identify some improvements that will substantially improve recall and precision.

Agile requirements handling in a service-oriented taxonomy of capabilities

To get to grips with information systems portfolio development, strategic decisions tend towards service orientation and cloud deployment. Functionality should be presented as services that can be consumed from secure clouds in a range of contexts, and service-oriented architectures should enable one to build and rebuild systems portfolios readily and rapidly. However, there is little practical guidance on how to organize and coordinate the multiple lines of work that developing, or modernizing to, a service-oriented portfolio entails. We outline a method framework that uses the structure of a service-oriented taxonomy of capabilities to organize requirements and development in terms of elaboration and refinement of requirements. The method compiles several best practices and supports independent, but integral, lines of work that can be organized in small-scale projects. We illustrate the framework on three cases that involve computer- and simulation-assisted business processes. We conclude that service-oriented capability taxonomies can be used to structure and discipline requirements handling at all levels, from enterprise strategy to technical systems. We suggest that our framework supports the development of capabilities and services that are persistent in the service-oriented sense relative to each other and to implementation. We suggest further that the framework supports collaborative work by facilitating shared conceptions across lines of work. We emphasize that empirical studies should be conducted to evaluate and refine the framework.

Proposition of an agile knowledge-based process model

Modern organizations generally define and use standardized models of their processes. They manage their activities using such standards. In these processes, the generalization and reuse of knowledge is facilitated by the standardization. But it is sometimes difficult to react to unexpected events due to over-constrained standards. Companies need to become agile to survive to continuous changes in their environments. There is a requirement of agility for the processes in order to ensure constant responsiveness and flexibility. This necessity of agility can be achieved through a knowledge-based system. Therefore, this article proposes a knowledge-based agile process model in which agility is driven by the reuse of knowledge and experiences. For this purpose, agility operators are defined as formalized pieces of knowledge. A model of an agile process in which these operators are used is presented. The basis of a methodology describing incremental versions of the model is also presented. This "versioning" allows to formalize experiences and to capitalize them for future reuse. Finally, an application of the method to the problem solving domain is presented. It is shown how the standard 9 Steps process becomes more agile by deploying the proposed methodology.

Quintessence of Traditional and Agile Requirement Engineering

Requirement gathering for software development project is the most crucial stage and thus requirement engineering (RE) occupies the chief position in the software development. Countless techniques concerning the RE processes exist to make sure the requirements are coherent, compact and complete in all respects. In this way different aspects of RE are dissected and detailed upon. A comparison of RE in Agile and RE in Waterfall is expatiated and on the basis of the literature survey the overall Agile RE process is accumulated. Agile being a technique produces high quality software in relatively less time as compared to the conventional waterfall methodology. The paramount objective of this study is to take lessons from RE that Agile method may consider, if quality being the cardinal concern. The study is patterned on the survey of the previous research reported in the coexisting literature and the practices which are being pursued in the area.

Dynamic Socio-technical System Design based on Stakeholder Interaction

In order to directly involve stakeholders in socio-technical system design, we argue for streamlining executable process specifications with business process modeling. Due to current agility requirements of organizations, socio-technical system development is considered one of the key activities of members of the organizations. Dynamic process adaptation enable handling the volatility of business operation and IT infrastructure. Subject-oriented process representations are key enablers to dynamic adaptation due to their capability for stakeholders to create directly executable models. In this way stakeholder can be involved in change management pro-actively. Subject-oriented models (i) represent all relevant features required for system control and decision making, and (ii) are executable on demand. This effectiveness enables organizational change in a creative and efficient way, while establishing innovative design and change management tools. Subject-oriented Business Process Management capabilities are reflected in this realm revealing benefits and potential for further research.

The mechanical and thermal setup of the GLORIA spectrometer

Abstract. The novel airborne Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) measures infrared emission of atmospheric trace constituents. GLORIA comprises a cooled imaging Fourier transform spectrometer, which is operated in unpressurized aircraft compartments at ambient temperature. The whole spectrometer is pointed by the gimbal towards the atmospheric target. In order to reach the required sensitivity for atmospheric emission measurements, the spectrometer optics needs to operate at a temperature below 220 K. A lightweight and compact design is mandatory due to limited space and high agility requirements. The cooled optical system needs to withstand high pressure and temperature gradients, humidity, and vibrations. A new cooling system based on carbon dioxide and liquid nitrogen combined with high-performance insulation has been developed to meet the mechanical, thermal, and logistical demands. The challenging mechanical and spatial requirements lead to the development of a novel rigid linear slide design in order to achieve the large optical path difference for high spectral resolution. This paper describes the mechanical and thermal setup of GLORIA and presents the performance results on two different research aircrafts.

Investigation of Adherence Degree of Agile Requirements Engineering Practices in Non-Agile Software Development Organizations

Requirements are critical for the success of software projects. Requirements are practically difficult to produce, as the hardest stage of building a software system is to decide what the system should do. Moreover, requirements errors are expensive to fix in the later phases of the software development life cycle. The rapidly changing business environment is highly challenging traditional Requirements Engineering (RE) practices. Most of the software development organizations are working in such dynamic environment, as a result, either by or without their awareness agile methodologies are adopted in various phases of their software development cycles. The aim of this paper is to investigate the adherence degree of agile RE practices in various software development organizations that are classifying themselves as adopting traditional (i.e. non-agile) software development methodologies. An approach is proposed for achieving this aim and it is applied on five different projects from four different organizations. The result shows that even the non-agile software development organizations are applying agile RE practices by different adherence degrees.

Erratum

Erratum to Ramesh, B., Cao, L., and Baskerville, R. (2010) Agile requirements engineering practices and challenges: an empirical study. Information Systems Journal, 20, 449–480. With apologies from the authors, the following reference is inadvertently missing from our article: Cao, L. and Ramesh, B. (2008) Benefits and challenges of agile requirements engineering practices: an empirical study. IEEE Software, 25(1), 60–67.

A comparative study of software tools for user story management

ContextUser stories have become widely accepted in agile software development. Consequently, a great number of software tools that provide, inter alia, support for practices based on user stories have emerged in recent years. These tools may have different features and focus in terms of support for agile requirements engineering (RE) concepts and practices. ObjectiveThe present study aims to provide a deep insight into the current capabilities and future trends of software support for agile RE practices based on user stories. MethodA comparative qualitative study of a set of agile software tools has been conducted according to the following criteria: coverage of the key functional requirements, support for basic agile RE concepts and practices, and user satisfaction with the tool. The criteria for tool selection were: diversity of software tools, high rating on the user-stories community Web site (http://www.userstories.com), and availability for review. ResultsThe results show a generally good coverage of key functional requirements related to management of user stories and epics, high-level release planning and low-level iteration planning. On the other hand, user-role modeling and persona support have not been addressed at all, and it has been found that requirements for acceptance testing support were completely covered by only one tool. More importantly, the study has revealed significant differences in the way different tools support agile RE concepts and practices (if at all). Finally, qualitative analysis of user reviews has demonstrated that practitioners prefer tools that are easy to set up, easy to learn, easy to use, and easy to customize, over more sophisticated but simultaneously more demanding tools. ConclusionAlthough the progress that has been made since the inception of these tools is quite clear, there is still room for improvements in terms of support for various agile RE practices within a specific agile process.

An Efficient Objective Quality Model for Agile Application Development

In the recent past, software industry has seen a paradigm shift in the software development methodologies. Several software development models have been proposed from time to time keeping in view the changing patterns and requirements of customers. Advancements in technology and change in standard operating procedures of corporate sector organizations has led to the development and evolution of several software development models. Currently, agile application development methodology is the most widely use software development model owing to its flexibility. Quality models have also evolved with corresponding to the software development models. Previously several quality metrics models have been developed for waterfall, spiral and incremental development. Work is also being done to propose a quality model which could ensure the quality of agile product being developed. However a robust and standard quality metrics model is lacking for the agile methodologies which can ensure that agile product being developed will fulfill implicit as well as explicit quality characteristics as agreed by the stakeholders. In this paper a quality metrics model for agile application development methodologies has been proposed which ascertains that the quality of the product being developed in agile requirement meet the standard and desired criteria of quality.

Derivation of agile SOA requirements using collaborative QFD

With the huge adoption and proliferation of applications using service–oriented architecture (SOA), design of distributed systems based on customer needs will be crucial to the success of organisations. Though it is realised that systems should be designed based on customer requirements, there is a need for systematic methodology, which can model end–to–end design from vision to execution. Such a methodology will prove more beneficial to large organisations with complex business requirements. In this paper, we have modified Blitz quality function deployment (QFD) methodology for collaborative SOA (CSOA) design based to provide Blitz–CSOA QFD. Injection of non–functional SOA requirement, house of quality (HOQ) matrix for relative prioritisation of SOA design requirements (including non–functional) based on normal and convex Saaty scale prioritisation and architects feedback decision matrix to determine agile requirements are the new key characteristics of Blitz–CSOA. The complete methodology is explained in detail along with derivations followed by a case study.

Assimilation of Four Layered Approach to NFR in Agile Requirement Engineering

In agile Requirement Engineering Techniques handling of non-functional requirements is ill defined. Customers or users talking about what they want the system to do normally do not think about resources, and other quality attributes. [1] This paper provides a solution to requirements related issues in agile environment and proposes an approach which integrates four layered approach to NFR with Agile Requirement Engineering that is helpful to improve requirement analysis process which would help in the prioritization of user stories. It also describes in detail the factors that could be considered for prioritization of user stories.

Modeling and Characteristics Research of Proportional-Valve Hydraulic Power Steering of Commercial Vehicle

Dynamics model of mechanical system and hydraulic system inclued electro-hydraulic proportional valve of Proportional-Valve Hydraulic Power Steering were established.and simulation model of assisted characteristic of PVHPS system was build .Response characteristic of proportional valve bypass flow was analyzed at different speed, and higher of the speed, greater of the flow in the bypass flow is . Steering wheel torque increases gradually as vehicle speed increases at the same wheel angle, and driver's better steering road feeling can be ensured. As wheel steering torque increases, assisted oil pressure increases and higher the speed is , slowly oil pressure increases, and assisted oil pressure increases quickly at low-speed steering condition, and increases slowly at high-speed condition,which meet the requirement of low-speed steering agility and high-speed road feeling.

Agile requirements engineering via paraconsistent reasoning

Innovative companies need an agile approach towards product and service requirements, to rapidly respond to and exploit changing conditions. The agile approach to requirements must nonetheless be systematic, especially with respect to accommodating legal and non-functional requirements. This paper examines how to support lightweight, agile requirements processes which can still be systematically modeled, analyzed and changed. We propose a framework, RE-KOMBINE, which is based on a propositional language for requirements modeling called Techne. We define operations on Techne models which tolerate the presence of inconsistencies. This paraconsistent reasoning is vital for supporting delayed commitment to particular design solutions. We evaluate these operations with an industry case study using two well-known formal analysis tools. Our evaluations show that the proposed framework scales to industry-sized requirements model, while still retaining (via propositional logic) the informality that is so useful during early requirements analysis.

Decision model for sustainable and agile resources management

Sustainability is nowadays an approach applicable in every area of company's activity including manufacturing, maintenance, logistics and others. It offers solutions referred to economic, environmental and social aspects providing limitation of resources use (thanks to changes in technology and equipment, especially important for natural and non-renewable resources), higher resources efficiency (thanks to decreased media and materials use, especially important for technical resources) and improved resources exploitation balance resulting in higher cost effectiveness, ecology ad human-centric approach. Agility on the other hand is the approach focused on meeting customers' demand concerning products' structure and logistics. It is a consequence of globalization, innovations in technology, products' lifecycle shortening and growing expectations and requirements of customers. Combining sustainability and agility is a difficult task, however potential results of such combination are key factors of success, including adaptability and flexibility of green and customer-oriented resources and processes. The following paper to present a decision model for resources management including sustainability criteria and meeting agility requirements.

Agile requirements prioritization in large-scale outsourced system projects: An empirical study

The application of agile practices for requirements prioritization in distributed and outsourced projects is a relatively recent trend. Hence, not all of its facets are well-understood. This exploratory study sets out to uncover the concepts that practitioners in a large software organization use in the prioritization process and the practices that they deem good. We seek to provide a rich analysis and a deep understanding of three cases in an exploratory study that was carried out in a large and mature company, widely recognized for its excellence and its engagement in outsourced software development. We used in-depth interviews for data collection and grounded theory techniques for data analysis. Our exploration efforts yielded the following findings: (i) understanding requirements dependencies is of paramount importance for the successful deployment of agile approaches in large outsourced projects. (ii) Next to business value, the most important prioritization criterion in the setting of outsourced large agile projects is risk. (iii) The software organization has developed a new artefact that seems to be a worthwhile contribution to agile software development in the large: ‘delivery stories’, which complement user stories with technical implications, effort estimation and associated risk. The delivery stories play a pivotal role in requirements prioritization. (iv) The vendor's domain knowledge is a key asset for setting up successful client-developer collaboration. (v) The use of agile prioritization practices depends on the type of project outsourcing arrangement. Our findings contribute to the empirical software engineering literature by bringing a rich analysis of cases in agile and distributed contexts, from a vendor's perspective. We also discuss the possible implications of the results for research and in practice.

Validating the Applicability of Agile Requirement Generation Model

We all know that agile methodology for software development is an alternative to waterfall methodology for software development. In today’s scenario, agile methods have caught the attention of software engineers worldwide. The reasons of this popularity are its iterative nature, quick delivery of software, face to face communication, less need of lengthy documentation etc. Agile methods focus on accommodating change even late in the development lifecycle. Though agile method are successfully applied on small softwares (whose development periods are less than 1-2 years), the main issue comes when someone want to apply agile methodology on large systems (development period greater than 2 years). One of the most important issues in the development of larger scale complex systems is accommodating changes to requirements. Someone proposed a soft-structured framework which combines the principles of agile and conventional software development that solves the issue of rapidly changing requirements for larger scale systems. The framework consists of two parts. First one is a soft structured requirements gathering approach that reflects the agile philosophy i.e. the Agile Requirements Generation Model and second one is a tailored development process that can be applied to either small or larger scale systems .The main work is to validate the applicability of the Agile RGM. So this paper validates the applicability of agile requirement generation model with the help of a project.