Two approaches to developing expert systems: A consideration of formal and semi-formal domains

The conventional approach to developing expert systems views the domain of application as being formally defined. This view often leads to practical problems when expert systems are built using this approach. This paper examines the implications and problems of the formal approach to expert system design and proposes an alternative approach based on the concept of semi-formal domains. This approach, which draws on the work of socio-technical information systems, provides guidelines which can be used for the design of successful expert systems.     

Reusable knowledge in security requirements engineering: a systematic mapping study

Security is a concern that must be taken into consideration starting from the early stages of system development. Over the last two decades, researchers and engineers have developed a considerable number of methods for security requirements engineering. Some of them rely on the (re)use of security knowledge. Despite some existing surveys about security requirements engineering, there is not yet any reference for researchers and practitioners that presents in a systematic way the existing proposals, techniques, and tools related to security knowledge reuse in security requirements engineering. The aim of this paper is to fill this gap by looking into drawing a picture of the literature on knowledge and reuse in security requirements engineering. The questions we address are related to methods, techniques, modeling frameworks, and tools for and by reuse in security requirements engineering. We address these questions through a systematic mapping study. The mapping study was a literature review conducted with the goal of identifying, analyzing, and categorizing state-of-the-art research on our topic. This mapping study analyzes more than thirty approaches, covering 20 years of research in security requirements engineering. The contributions can be summarized as follows: (1) A framework was defined for analyzing and comparing the different proposals as well as categorizing future contributions related to knowledge reuse and security requirements engineering; (2) the different forms of knowledge representation and reuse were identified; and (3) previous surveys were updated. We conclude that most methods should introduce more reusable knowledge to manage security requirements.     

Constructing and revising formal arguments in requirements engineering

Confidence that a proposed software-based system, once implemented, will be successful in its environment can be given through a formal argument, typically proof in a formal language. Problems with such arguments include the need to account for the relationships between different kinds of model (models of the proposed system, of assumptions concerning its environment, and of the joint properties, or requirements, which the system should achieve with its environment), and the need to revise these models within an exploratory requirements engineering process. This paper investigates the assumption/commitment style of modelling, originally developed for reasoning about interference in concurrent systems, for developing such arguments. The style, using a simple temporal logic, is used to express these models, with an associated compositional reasoning method allowing arguments to be constructed, and revised with minimal re-work of proof. Some conclusions are drawn concerning the benefits of, and problems with, this approach. The approach is illustrated with a meeting-scheduler example.     

A systematic review of security requirements engineering

One of the most important aspects in the achievement of secure software systems in the software development process is what is known as Security Requirements Engineering. However, very few reviews focus on this theme in a systematic, thorough and unbiased manner, that is, none of them perform a systematic review of security requirements engineering, and there is not, therefore, a sufficiently good context in which to operate. In this paper we carry out a systematic review of the existing literature concerning security requirements engineering in order to summarize the evidence regarding this issue and to provide a framework/background in which to appropriately position new research activities.     

Preface of the special issue on formal methods in industrial critical systems

International Journal on Software Tools for Technology Transfer - The use of formal methods in industrial critical systems has a lot of potential to increase the quality and reliability of these...     

A comparison of security requirements engineering methods

This paper presents a conceptual framework for security engineering, with a strong focus on security requirements elicitation and analysis. This conceptual framework establishes a clear-cut vocabulary and makes explicit the interrelations between the different concepts and notions used in security engineering. Further, we apply our conceptual framework to compare and evaluate current security requirements engineering approaches, such as the Common Criteria, Secure Tropos, SREP, MSRA, as well as methods based on UML and problem frames. We review these methods and assess them according to different criteria, such as the general approach and scope of the method, its validation, and quality assurance capabilities. Finally, we discuss how these methods are related to the conceptual framework and to one another.     

Modeling NASA swarm-based systems: using agent-oriented software engineering and formal methods

The need to collect new data and perform new science is causing the complexity of NASA missions to continually increase. This complexity needs to be controlled via new technological advancements and balanced with a reduction in mission and operation costs. Planned and hypothesized missions involve self-management, biological-inspiration based on swarms, and autonomous operation as a means of achieving these goals. We consider a tailored software engineering approach to developing such systems based on agent-oriented software engineering and formal methods. We report on advances in modeling, implementing, and testing NASA swarm-based concept missions.     

Model-driven engineering for mobile robotic systems: a systematic mapping study

Software and Systems Modeling - Mobile robots operate in various environments (e.g. aquatic, aerial, or terrestrial), they come in many diverse shapes and they are increasingly becoming parts of...     

A requirements engineering framework for cross-organizational ERP systems

The development of cross-organizational enterprise resource planning (ERP) solutions is becoming increasingly critical to the business strategy of many networked companies. The major function of cross-organizational ERP solutions is to coordinate work in two or more organizations. However, how to align ERP application components and business requirements for coordination and cooperation is hardly known. This paper reports on the outcomes of applying a coordination theory perspective to an analysis of the ERP misalignment problem. We present a conceptual framework for analyzing coordination and cooperation requirements in inter-organizational ERP projects. The framework makes explicit the undocumented built-in assumptions for coordination and cooperation that may have significant implications for the ERP adopters and incorporates a library of existing coordination mechanisms supported by modern ERP systems. We use it to develop a proposal for how to achieve a better alignment between ERP implementations and supported business coordination processes in inter-organizational settings. We report on some early assessments of the implications of our framework for practicing requirements engineers. Both our framework and library rest on a literature survey and the first author’s experience with ERP implementation. In future empirical research, we will further validate and refine our framework.     

Experience with formal methods in critical systems

Although there are indisputable benefits to society from the introduction of computers into everyday life, some applications are inherently risky. Worldwide, regulatory agencies are examining how to assure safety and security. This study reveals the applicability and limitations of formal methods     

Using formal methods with SysML in aerospace design and engineering

Maintaining design consistency is a critical issue for macro-level aerospace development. The inability to maintain design consistency is a major contributor to cost and schedule overruns. By embedding The Systems Modeling Language (SysML) within a formal logic, formal methods can be used to maintain consistency as a design evolves. SysML, provided with a formal semantics, enables engineers to employ reasoning in the course of a typical model-based development process. Engineers can make use of formal methods within the context of current engineering practice and tools without needing to have special formal methods training. As component subsystems are introduced to refine a design, their assumptions are checked against current assumptions. If new assumptions do not introduce inconsistency, they are added to the model assumptions. If the assumptions render the design inconsistent, they are detected which minimizes potential rework. SysML has a demonstrated capability for top-to-bottom design refinement for large-scale aerospace systems. SysML does not have a formal logic-based semantics. The logical formalism within which SysML is embedded matches the informal semantic of SysML closely. The approach to integrating formal methods with SysML is illustrated with a typical macro-level aerospace design task. The design process produces a design solution which provably satisfies the top level requirements. The example provides evidence that coupling formal methods with SysML can realistically be applied to solve aerospace development problems. The approach results from a number of detailed design trades employing a model-based system development process which used SysML as the model integration framework.     

A systematic literature review of stakeholder identification methods in requirements elicitation

This paper presents a systematic review of relevant published studies related to topics in Requirements Engineering, specifically, concerning stakeholder identification methods in requirements elicitation, dated from 1984 to 2011. Addressing four specific research questions, this systematic literature review shows the following evidence gathered from these studies: current status of stakeholder identification in software requirement elicitation, the best practices recommended for its performance, consequences of incorrect identification in requirements quality, and, aspects which need to be improved. Our findings suggest that the analyzed approaches still have serious limitations in terms of covering all aspects of stakeholder identification as an important part of requirements elicitation. However, through correctly identifying and understanding the stakeholders, it is possible to develop high quality software.     

A systematic mapping study of API usability evaluation methods

An Application Programming Interface (API) provides a programmatic interface to a software component that is often offered publicly and may be used by programmers who are not the API’s original designers. APIs play a key role in software reuse. By reusing high quality components and services, developers can increase their productivity and avoid costly defects. The usability of an API is a qualitative characteristic that evaluates how easy it is to use an API. Recent years have seen a considerable increase in research efforts aiming at evaluating the usability of APIs. An API usability evaluation can identify problem areas and provide recommendations for improving the API. In this systematic mapping study, we focus on 47 primary studies to identify the aim and the method of the API usability studies. We investigate which API usability factors are evaluated, at which phases of API development is the usability of API evaluated and what are the current limitations and open issues in API usability evaluation. We believe that the results of this literature review would be useful for both researchers and industry practitioners interested in investigating the usability of API and new API usability evaluation methods.     

Applying formal verification to the AAMP5 microprocessor: A case study in the industrial use of formal methods

Formal specification combined with mechanical verification is a promising approach for achieving the extremely high levels of assurance required of safety-critical digital systems. However, many questions remain regarding their use in practice: Can these techniques scale up to industrial systems, where are they likely to be useful, and how should industry go about incorporating them into practice? This paper discusses a project undertaken to answer some of these questions, the formal verification of the microcode in the AAMP5 microprocessor. This project consisted of formally specifying in the PVS language a Rockwell proprietary microprocessor at both the instruction-set and register-transfer levels and using the PVS theorem prover to show the microcode correctly implemented the instruction-level specification for a representative subset of instructions. Notable aspects of this project include the use of a formal specification language by practicing hardware and software engineers, the integration of traditional inspections with formal specifications, and the use of a mechanical theorem prover to verify a portion of a commercial, pipelined microprocessor that was not explicitly designed for formal verification.     

Quality requirements engineering for systems and software architecting: methods, approaches, and tools

Requirements engineering and software architecture are quite mature software engineering sub-disciplines, which often seem to be disconnected for many reasons and it is difficult to perceive the impact of functional and non-functional requirements on architecture and to establish appropriate trace links for traceability purposes. In other cases, the estimation of how non-functional requirements, as the quality properties a system should pose, is not perceived useful enough to produce high-quality software. Therefore, in this special issue, we want to highlight the importance and the role of quality requirements for architecting and building complex software systems that in many cases require multidisciplinary engineering techniques, which increases the complexity of the software development process.     

Paradigms for knowledge-based systems in industrial engineering

When developing expert systems, expertise lies not only in formulating the knowledge to be put into the knowledge base, but also in deciding upon the knowledge representation and inference mechanism most suited to the application. Six detailed knowledge bases demonstrate the application of various AI-based systems to industrial engineering problems. They illustrate a number of approaches: expert systems, which are based upon practical experience; decision systems, which derive from modelling skills; and situation-action systems, which rely on production process design skills. The six paradigms presented describe a logical expert system for selecting material handling equipment; a multi-valued expert system for selecting a dispatching rule for automatic guided vehicles; a profile matching expert system for selecting project management software; a confidence building expert system for selecting a machine feeder; a tandem decision system for developing a production schedule; and a situation-action system for controlling job allocation in a flexible manufacturing cell. The relationships between these various paradigms and the characteristics of problems to which they can be applied are categorized by the nature of the expert and his expertise; the features of the environment; the decision or decisions to be taken; and the manner in which AI-system performance can be evaluated. A knowledge base is proposed for determining which architecture is most appropriate for a given application.