Requirement engineering techniques in developing expert systems

Adoption of the most suitable requirements engineering (RE) process and selection of the most appropriate RE techniques for a given project are challenging issues for industry. In order to alleviate the problems, a framework for RE process development (FRERE) was developed based on our research in the last six years. The overall architecture of the framework and a brief case study are presented in the paper. The framework addresses several core issues of the RE process: engineering issues, domain issues, characteristics of the software project, and issues of conformity to software process standards. FRERE consists of three parts: (1) The RE process knowledge base (REPKB) which contains RE process knowledge, (2) methodologies which provide guidance to develop a customized software process model in an iterative way; and (3) assessment models which provide information about the suitability of the newly developed RE process model for the software project under development.

This paper identifies the essential components of a requirements engineering (RE) process and provides alternatives to the requirements analyst when deciding on a particular set of RE methods. Existing methods of choosing RE techniques are discussed, and a new technique is proposed specifically for choosing RE techniques for projects with critical time-to-market projects. The components of the essential RE process as well as many other insights into the practice of RE were identified by examining the current literature and by analyzing the data from 25 completed surveys concerning the area of RE. The survey data provides insight into the state of the practice in requirements engineering.

The first argument presented is that if we have a clear understanding of the objectives of the requirements engineering (RE) process then we can identify what techniques we need. No single method or technique will be sufficient. The second argument is that a key objective of the RE process is to specify a system which will ultimately be successful. Three common types of failure are examined: process failure, expectation failure and interaction failure. The third argument is that if the causes of each type of failure can be described then we will be able to identify what techniques are needed to help us avoid failure. The five common causes are described: the requirements engineering process itself, human communication within requirements, knowledge development, documentation of requirements and management. A discussion of each cause is followed by a list of the RE techniques needed. The paper concludes with a 'wish list' of seventy requirements for RE techniques, and a brief discussion of the strengths and weaknesses of the RE community in meeting those requirements.

Requirements Engineering (RE) has established itself as a software engineering discipline during the past decades. While researchers have been investigating the RE discipline with a plethora of empirical studies, attempts to systematically derive an empirically-based theory in context of the RE discipline have just recently been started. However, such a theory is needed if we are to define and motivate guidance in performing high quality RE research and practice. We aim at providing an empirical and valid foundation for a theory of RE, which helps software engineers establish effective and efficient RE processes. We designed a survey instrument and theory that has now been replicated in 10 countries world-wide. We evaluate the propositions of the theory with bootstrapped confidence intervals and derive potential explanations for the propositions. We report on the underlying theory and the full results obtained from the replication studies with participants from 228 organisations. Our results represent a substantial step forward towards developing an empirically-based theory of RE giving insights into current practices with RE processes. The results reveal, for example, that there are no strong differences between organisations in different countries and regions, that interviews, facilitated meetings and prototyping are the most used elicitation techniques, that requirements are often documented textually, that traces between requirements and code or design documents is common, requirements specifications themselves are rarely changed and that requirements engineering (process) improvement endeavours are mostly intrinsically motivated. Our study establishes a theory that can be used as starting point for many further studies for more detailed investigations. Practitioners can use the results as theory-supported guidance on selecting suitable RE methods and techniques.

Requirements engineering (RE) process improvement methods typically work with explicit process models describing activities and document flow between the stakeholders involved, and with explicit document definitions. In complex, multi-project contexts, however, the RE process is better characterized as intertwining of design, negotiation, and sense-making. In the first part of This work, we present the concepts of a workshop-based RE process improvement technique suitable for a multi-project context. In the second part, we show the experiences made in an industrial case study conducted with Nokia smart traffic products. The major innovations of our approach are: (i) instead of a process model, an information model is created, which focuses solely on the responsibilities of stakeholders with regard to the major documents; (ii) instead of document details, only the major point of view of the documents is defined.

An agile approach for managing requirements change to improve learning and adaptability

In global software development (GSD), teams from different geographies are involved in software development activities from requirement till management phase. There are many potential benefits associated with GSD environment such as development cost, round the clock development, accessibility to better skilled people and many others. Although, organizations are achieving the benefits of GSD but its challenging nature such as cultural and language differences, trust relationship, coordination and communication is introducing numerous challenges that cannot be ignored. These challenges are significantly influencing requirement engineering (RE) process in GSD. One of the reasons behind challenging nature of RE in GSD is varying situational contexts such as social, communication and cultural contexts, language, human, technical and management related contexts. This necessitate for a comprehensive framework that demonstrates the perspective of situational contexts. This study aims to review the existing situational RE frameworks, highlights the reported situational contexts and provide future research directions. The literature revealed that the situational contexts are commonly related to twelve categories that include stakeholders, organization, requirements, project, management, risk, culture, standard, task, communication, technique and methods, and innovation. The situational contexts related to these categories show the main standpoint of situational software development in GSD. These situational contexts are significant for improving competencies of the team members while performing RE process in GSD environment. This study also draws attention towards some imperative research directions for further studies in line of situational software engineering.

The emergence of Systems of Systems (SoSs) and Systems of Systems Engineering (SoSE) is largely driven by global societal needs including energy-water-food nexus, population demographics, global climate, integrated transport, security and social activity. However, due to their scale, structural and functional complexity and emergent properties, these global spanning Cyber-Physical Systems of Systems are becoming increasingly complex and more difficult for current requirements engineering (RE) practices to handle. In this paper, we firstly introduce SoSE as an emerging discipline and key characteristics of SoSs. We then highlight the challenges that the RE discipline must respond to. We discuss some weaknesses of current RE techniques and approaches to cope with the complexity of SoSs. We then argue that there is a need for the global RE community to evolve current RE approaches and to develop new ways of thinking, new RE capabilities and possibly a new RE science as a key mechanism for addressing requirements engineering complexities posed by Systems of Systems. We then outline a requirements engineering perspective and research agenda that identifies 'top-10' research themes informed by a cluster of four Systems of Systems Engineering projects funded by the European Commission's Horizon 2020 research programme.

Usability and requirements engineering both provide means for discovering, analyzing, and fulfilling users' needs. In practice, it is difficult to manage and control user-centered design and system development processes separately. Based on a case study conducted in two software product companies, we have aimed to understand the role of usability specialists in the requirements engineering (RE) process. Our findings indicate that usability is still often seen as user interface design instead of a more comprehensive characteristic of a software product. Therefore, usability specialists had difficulties participating in early RE activities. To integrate usability as a natural part of the RE process, the usability teams have started to organize training in their companies. The main purpose of the training is to ensure that usability is not relying solely on the work of specialists but becomes a common responsibility for the whole product development organization.

Software development requires intensive communication between the requirements engineers and software stakeholders, particularly during the Requirements Engineering (RE) phase. Therefore, the individuals' culture might influence both the RE process and the result. Our aims are to investigate the extend of cultural influences on the RE process, and to analyze how the RE process can be adapted to take into account cultural aspects. The model we present is based on Hofstede's cultural theory. The model was applied on a pilot case study in the context of the conservative Saudi Arabian culture. The results reveal 6 RE aspects and 10 cultural factors that have a large impact on the RE practice.

An efficient solids control procedure or mechanism is one of the keys to drilling optimization. This can be achieved by employing proper solids control equipment while drilling is in progress. This paper presents an expert system that is developed for the selection of proper solids control equipment. An expert system is an interactive computer based tool that simulates the thought process of human experts to solve complex problems in a specific domain. The key stages in the development include: problem definition and analysis, knowledge acquisition (involving consultation with experts), knowledge-base development, interface development, and finally input and output data presentation. The expert system developed has four important modules. The first module is based on an extensive survey of the literature available on the subject to date. Upon input from its user, it suggests the best possible combination of solids control equipment that is compatible with the drilling parameters. The second module helps the user in carrying out density control calculations pertaining to solid control. The third module is in a text mode, and describes the solids control equipment commonly installed on the rigs, along with the criterion involved in their application. The fourth module allows the user to note down his experience pertaining to any particular situation he may have come across. This can be of help to him, or to any other user who may be faced with a similar situation later. This paper presents the methodology and various examples under these four modules to demonstrate field related applications. The salient features on this expert system are its " userfriendliness" and ability to constantly self-improve itself constantly by maintaining a " dynamic memory." A listing of the program is included in this paper to allow readers to validate the technique and gain benefit of the paper. At the rig site, this system will allow the user to familiarize himself with the solids control equipment. This will help in obtaining the best possible equipment arrangement for effective solids control and various density control calculations. Introduction Selection of the right kind of drilling fluid is essential for economic drilling of wells. During drilling, drilled solids or cuttings generated at the bit, mix and interact with the initially formulated drilling fluid, and bring about changes in its density, rheology, and other properties of the fluid. These factors, in turn, are determined by such interacting variances as lithology, fluid properties, penetration rate and the wellbore geometry. Several studies(1-8) mention the disadvantages related to poor solids removal while the drilling is in progress. These include higher density, higher viscosity, higher filtration rate, and higher filter cake thickness. Practically, this means lower rates of penetration, reduction in bit-bearing life, higher torque and drag and more chances of stuck pipe. Definitely, this is uneconomical for drilling operations. A large number of variables are often involved in deciding the type of solids control equipment that has to be employed for a particular kind of drilling situation.

Requirements Engineering (RE) discipline deals with elicitation, analysis, specification, validation and management of requirements. Several ontology-driven approaches have been proposed to improve these RE activities. However, the requirements engineering community still lacks a comprehensive understanding on how ontologies are used in RE process. The objective of this work is to explore how ontologies are employed in requirements engineering, aiming to identify the main phases addressed, the languages that have been used, the types of existing contributions, as well as the requirements modeling styles have been used and the benefits of using ontology in RE. We conducted a systematic literature review to identify the primary studies on the use of ontologies in RE, following a pre-defined review protocol. Sixty-six papers were selected, covering the five main RE process phases. Moreover, we have identified thirteen ontology-related languages. Furthermore, twenty-six empirical studies have been identified which provided evidence of five group of benefits. The main findings of this review are: (1) there are empirical evidences to state that ontologies benefit RE activities in both academy and industry settings, helping to reduce ambiguity, inconsistency and incompleteness of requirements; (2) the vast majority of papers do not meet all RE phases; (3) nearly half of the papers use W3C recommended languages; (4) the majority of contributions are supported by a tool; and (5) there is a great diversity of requirements modeling styles supported by ontologies.

Software projects typically require effort estimation from the software development life cycle (SDLC) staff at the commencement of the software development activities. Inaccuracies in effort estimation of software projects early on in the SDLC continues to be a perennial problem. Typically, improved estimates for software projects are provided under circumstances where requirements engineering (RE) is completed. RE provides a key reference in the form of requirements for the estimation process. However, RE by itself may consume significant effort demanding the RE phase to be estimated as the first step in the SDLC. It is difficult to establish RE estimates, as RE usually has no tangible reference on which estimates can be based. This paper provides a practical estimation method for large and complex RE processes. We demonstrate using a case study snapshot in a large software organization that the method provides improved effort estimates for the RE process.

The requirements for corrosion expert systems have never been clearly stated, though many expert system developers must have had a “typical” user in mind, when designing their application. Reviewing some of the developed systems has shown that there exist quite some different approaches. In this paper, some general guidelines will be presented which pertain both to the development of expert systems in general, as well as to the development of expert systems for corrosion, in particular. Most of these guidelines stem from experience with the development of a large-scale expert system for materials selection and corrosion analysis, PRIME. The following topics will be discussed: concepts that affect design and construction, architectural issues, the selection of requisite expert system components in conjunction with user requirements, design issues affected by task type and organizational constraints.

The aim of this tutorial is to explain in an accessible manner the psychology of people in the context of misunderstandings, politics and social issues that affect software development. It focuses on user-stakeholder interaction techniques for analysis and interpretation of human behaviour, and how psychological knowledge can be used to improve the requirements engineering (RE) process as well as interpreting the implications of human motivations and values for requirements and software systems architecture. Soft issues, such as politics and people's feelings, are often cited as problems in the RE process and as key causes of system failure. It is clear from the RE literature that understanding user beliefs and values is vital for the success of software development. The London Ambulance service is a canonical example of system failure caused, in part, by inadequate understanding of ambulance crews' motivations, values of self esteem and autonomy, and the emotional reaction to lack of involvement in the requirements process, leading to technology failure.