Requirement decomposition and traceability

When producing large systems, it is important that the requirement decomposition process is performed correctly, with requirement traceability maintained. This paper explores this area, using examples from industry to illustrate the problems which can be encountered if traceability/decomposition is not performed correctly. It is hoped that this paper will assist the reader in generating a more precise definition of some general system engineering concerns such as when decomposition needs to be performed, with the requirements hierarchy extended. For the problems covered, this paper also suggests methods by which they can be alleviated or recognised once they have occurred. This additional information is primarily aimed at people who are using tools to manage their requirements, as there may be mechanisms to automate these methods. This paper presents the personal view of the author, based on his many years of experience in this area.     

An industrial case study in reconstructing requirements views

Requirements views, such as coverage and status views, are an important asset for monitoring and managing software development projects. We have developed a method that automates the process of reconstructing these views, and we have built a tool, ReqAnalyst, that supports this method. This paper presents an investigation as to which extent requirements views can be automatically generated in order to monitor requirements in industrial practice. The paper focuses on monitoring the requirements in test categories and test cases. In order to retrieve the necessary data, an information retrieval technique, called Latent Semantic Indexing, was used. The method was applied in an industrial study. A number of requirements views were defined and experiments were carried out with different reconstruction settings for generating these views. Finally, we explored how these views can help the developers during the software development process.

Transforming and tracing reused requirements models to home automation models

ContextModel-Driven Software Development (MDSD) has emerged as a very promising approach to cope with the inherent complexity of modern software-based systems. Furthermore, it is well known that the Requirements Engineering (RE) stage is critical for a project’s success. Despite the importance of RE, MDSD approaches commonly leave textual requirements specifications to one side.ObjectiveOur aim is to integrate textual requirements specifications into the MDSD approach by using the MDSD techniques themselves, including metamodelling and model transformations. The proposal is based on the assumption that a reuse-based Model-Driven Requirements Engineering (MDRE) approach will improve the requirements engineering stage, the quality of the development models generated from requirements models, and will enable the traces from requirements to other development concepts (such as analysis or design) to be maintained.MethodThe approach revolves around the Requirements Engineering Metamodel, denominated as REMM, which supports the definition of the boilerplate based textual requirements specification languages needed for the definition of model transformation from application requirements models to platform-specific application models and code.ResultsThe approach has been evaluated through its application to Home Automation (HA) systems. The HA Requirement Specification Language denominated as HAREL is used to define application requirements models which will be automatically transformed and traced to the application model conforming to the HA Domain Specific Language.ConclusionsAn anonymous online survey has been conducted to evaluate the degree of acceptance by both HA application developers and MDSD practitioners. The main conclusion is that 66.7% of the HA experts polled strongly agree that the automatic transformation of the requirements models to HA models improves the quality of the HA models. Moreover, 58.3% of the HA participants strongly agree with the usefulness of the traceability matrix which links requirements to HA functional units in order to discover which devices are related to a specific requirement. We can conclude that the experts we have consulted agree with the proposal we are presenting here, since the average mark given is 4 out of 5.     

Tracing requirements to defect reports: an application of information retrieval techniques

To support debugging, maintenance, verification and validation (V&V) and/or independent V&V (IV&V), it is necessary to understand the relationship between defect reports and their related artifacts. For example, one cannot correct a code-related defect report without being able to find the code that is affected. Information retrieval (IR) techniques have been used effectively to trace textual artifacts to each other. This has generally been applied to the problem of dynamically generating a trace between artifacts in the software document hierarchy after the fact (after development has proceeded to at least the next lifecycle phase). The same techniques can also be used to trace textual artifacts of the software engineering lifecycle to defect reports. We have applied the term frequency–inverse document frequency (TF-IDF) technique with relevance feedback, as implemented in our requirements tracing on-target (RETRO) tool, to the problem of tracing textual requirement elements to related textual defect reports. We have evaluated the technique using a dataset for a NASA scientific instrument. We found that recall of over 85% and precision of 69%, and recall of 70% and precision of 99% could be achieved, respectively, on two subsets of the dataset.     

Advanced product planning: a comprehensive process for systemic definition of new product requirements

This paper reports results of research into the definition of requirements for new consumer products––specifically, electro-mechanical products. The research dealt with the derivation of design requirements that are demonstrably aligned with stakeholder needs. The paper describes a comprehensive process that can enable product development teams to deal with statements of product requirements, as originally collected through market research activities, in a systematic and traceable manner from the early, fuzzy front end, stages of the design process. The process described has been based on principles of systems engineering. A case study from its application and evaluation drawn from the power sector is described in this paper. The case study demonstrates how the process can significantly improve product quality planning practices through revision of captured product requirements, analysis of stakeholder requirements and derivation of design requirements. The paper discusses benefits and issues from the use of the process by product development teams, and identifies areas for further research. Finally, the conclusions drawn from the reported research are presented.

非功能需求的结构化定义以及概念性追踪管理框架

针对需求工程中非功能需求概念非常模糊甚至相互矛盾、非功能需求与其他非功能需求及功能需求之间的关系繁复而难以分析和建模、非功能需求与设计阶段制品之间的追踪关系模糊而不易记录和维护等问题,分析了与非功能需求相关的概念在需求分析阶段和体系结构设计阶段的表现形式,给出了一个结构化的非功能需求定义;规范了不同类型需求之间的各种复杂关系,建立了一个跨越分析和设计阶段的概念性非功能需求追踪管理框架,规范了需求分析和体系结构设计阶段与非功能需求相关的概念和制品之间的关系。提出的结构化定义以及概念性追踪管理框架明确地刻画了非功能需求概念的外延,为简化需求模型以及进一步研制系统化、实用化的非功能需求建模及追踪管理技术奠定了理论基础。     

An integrative approach to requirements analysis: How task models support requirements reuse in a user-centric design framework

Many software systems fail to address their intended purpose because of a lack of user involvement and requirements deficiencies. This paper discusses the elaboration of a requirements-analysis process that integrates a critical-parameter-based approach to task modeling within a user-centric design framework. On one hand, adapting task models to capture requirements bridges the gap between scenarios and critical parameters which benefits design from the standpoint of user involvement and accurate requirements. On the other hand, using task models as a reusable component leverages requirements reuse which benefits design by increasing quality while simultaneously reducing development costs and time-to-market. First, we present the establishment of both a user-centric and reuse-centric requirements process along with its implementation within an integrated design tool suite. Secondly, we report the design, procedures, and findings of two user studies aimed at assessing the feasibility for novice designers to conduct the process as well as evaluating the resulting benefits upon requirements-analysis deliverables, requirements quality, and requirements reuse.     

A streamlined, cost-effective database approach to manage requirements traceability

Requirements traceability offers many benefits to software projects, and it has been identified as critical for successful development. However, numerous challenges exist in the implementation of traceability in the software engineering industry. Some of these challenges can be overcome through organizational policy and procedure changes, but the lack of cost-effective traceability models and tools remains an open problem. A novel, cost-effective solution for the traceability tool problem is proposed, prototyped, and tested in a case study using an actual software project. Metrics from the case study are presented to demonstrate the viability of the proposed solution for the traceability tool problem. The results show that the proposed method offers significant advantages over implementing traceability manually or using existing commercial traceability approaches.     

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.     

Change impact analysis for requirements: A metamodeling approach

ContextFollowing the evolution of the business needs, the requirements of software systems change continuously and new requirements emerge frequently. Requirements documents are often textual artifacts with structure not explicitly given. When a change in a requirements document is introduced, the requirements engineer may have to manually analyze all the requirements for a single change. This may result in neglecting the actual impact of a change. Consequently, the cost of implementing a change may become several times higher than expected.ObjectiveIn this paper, we aim at improving change impact analysis in requirements by using formal semantics of requirements relations and requirements change types.MethodIn our previous work we present a requirements metamodel with commonly used requirements relation types and their semantics formalized in first-order logic. In this paper the classification of requirements changes based on structure of a textual requirement is provided with formal semantics. The formalization of requirements relations and changes is used for propagating proposed changes and consistency checking of proposed changes in requirements models. The tool support for change impact analysis in requirements models is an extension of our Tool for Requirements Inferencing and Consistency Checking (TRIC).ResultsThe described approach for change impact analysis helps in the elimination of some false positive impacts in change propagation, and enables consistency checking of changes.ConclusionWe illustrate our approach in an example which shows that the formal semantics of requirements relations and change classification enables change alternatives to be proposed semi-automatically, the reduction of some false positive impacts and contradicting changes in requirements to be determined.     

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.     

Managing requirements conflicts in software product lines: A goal and scenario based approach

The product line approach is recognized as a successful approach to reuse in software development. However, in many cases, it has resulted in interactions between requirements and/or features. Interaction detection, especially conflict detection between requirements has become more challenging. Thus, detecting conflicts between requirements is essential for successful product line development. Formal methods have been proposed to address this problem, however, they are hard to understand by non-experts and are limited to restricted domains. In addition, there is no overall process that covers all the steps for managing conflicts. We propose an approach for systematically identifying and managing requirements conflicts, which is based on requirements partition in natural language and supported by a tool. To demonstrate its feasibility, the proposed approach has been applied to the home integration system (HIS) domain and the results are discussed.     

Development of a computer-based interviewing tool to enhance the requirements gathering process

Software design is an area where it is most important to elicit an accurate and complete set of requirements. Determining the users requirements and their qualitative satisfaction with a developing product are two major problems which arise, often due to the different backgrounds and perspectives of the different stakeholders, including the software engineer, the domain expert and the end-user. Involving users throughout the design and development process is an essential part of any project. Computer-based interviewing has been found to be a valuable tool in eliciting information, which can also enhance interpersonal communication afterwards. This paper discusses the development of a computer interviewing tool to facilitate the gathering of user requirements and conducting user evaluations.     

基于混合模式的农产品质量安全可追溯系统集成方法*

为了提升农产品质量安全管理水平,提出一种基于混合模式的农产品质量安全可追溯系统的集成方法。该方法采用C/S和B/S混合模式来构架系统,采用射频识别（RFID）和条码技术对产品进行标志、信息采集和传输,使用组件技术开发系统关键模块;最后以蔬菜为例,在对某企业实地调研的基础上,应用此方法开发了一套蔬菜质量安全可追溯系统。运行结果表明系统将供应链各部分有机联系,保证了农产品在整个供应链流动时信息流的准确、通畅和实时,实现了农产品的质量安全可追溯功能。     

Development of a new software for comprehensive management and traceability of hospital radiopharmacies

A database software application for comprehensive management and traceability of hospital radiopharmacies has been developed and implemented. This software is a customizable shareware called Radiolab, which provides an immediate and complete traceability of all preparations, controls and radiopharmaceuticals, as well as a great help in the management of reports, orders, stock and radioactive waste. Available by now in five languages (English, Spanish, French, Portuguese and Italian) this software and its manual can be downloaded from the Internet at www.radiopharmacy.net.     

Assessing a requirements evolution approach: Empirical studies in the air traffic management domain

Requirements evolution is still a challenging problem in engineering practices. In this paper, we report the results of the empirical evaluation of a novel approach for modeling and reasoning on evolving requirements. We evaluated the effectiveness of the approach in modeling requirements evolution by means of a series of empirical studies in the air traffic management (ATM) domain. As we also wanted to assess whether the knowledge of the method and/or the application domain influences the effectiveness of the approach, the studies involved researchers, master students and domain experts with different level of knowledge of the approach and of the ATM domain. The participants have applied the approach to a real evolutionary scenario which focuses on the introduction of a new queue management tool, the Arrival MANager (AMAN) and a new network for information sharing (SWIM) connecting the main ATM actors. The results from the studies show that the modeling approach is effective in capturing requirements evolution. In addition, domain knowledge and method knowledge do not have an observable effect on the effectiveness of the approach. Furthermore, the evaluation provided us useful insights on how to improve the modeling approach.     

A case study validation of a knowledge-based approach for the selection of requirements engineering techniques

Requirements engineering (RE) is a critical phase in the software engineering process and plays a vital role in ensuring the overall quality of a software product. Recent research has shown that industry increasingly recognizes the importance of good RE practices and the use of appropriate RE techniques. However, due to the large number of RE techniques, requirements engineers find it challenging to select suitable techniques for a particular project. Unfortunately, technique selection based on personal experience has limitations with regards to the scope, effectiveness and suitability of the RE techniques for the project at hand. In this paper, a Knowledge-based Approach for the Selection of Requirements Engineering Techniques (KASRET) is proposed that helps during RE techniques selection. This approach has three major features. First, a library of requirements techniques was developed which includes detailed knowledge about RE techniques. Second, KASRET integrates advantages of different knowledge representation schemata and reasoning mechanisms. Thus, KASRET provides mechanisms for the management of knowledge about requirements techniques and support for RE process development. Third, as a major decision support mechanism, an objective function evaluates the overall ability and cost of RE techniques, which is helpful for the selection of RE techniques. This paper makes not only a contribution to RE but also to research and application of knowledge management and decision support in process development. A case study using an industrial project shows the support of KASRET for RE techniques selection.