Model-based engineering for change-tolerant systems

Developing and evolving today’s systems are often stymied by the sheer size and complexity of the capabilities being developed and integrated. At one end of the spectrum, we have sophisticated agent-based software with hundreds of thousands of collaborating nodes. These require modeling abstractions relevant to their complex workflow tasks as well as predictable transforms and mappings for the requisite elaborations and refinements that must be accomplished in composing these systems. At the other end of the spectrum, we have ever-increasing capabilities of reconfigurable hardware devices such as field-programmable gate arrays to support the emerging adaptability and flexibility needs of these systems. From a model-based engineering perspective, these challenges are very similar; both must move their abstraction and reuse levels up to meet growing productivity and quality objectives. Model-based engineering and software system variants such as the model-driven architecture (MDA) are increasingly being applied to systems development as the engineering community recognizes the benefits of managing complexity, separating key concerns, and automating transformations from high-level abstract requirements down through the implementation. However, there are challenges when it comes to establishing the correct boundaries for change-tolerant parts of the system. Capabilities engineering (CE) is a promising approach for defining long-lived components of a system to ensure some sense of change tolerance. For innovative initiatives such as the National Aeronautics and Space Administration (NASA)’s autonomous nanotechology swarms (ANTS), the development and subsequent evolution of such systems are of considerable importance as their missions involve complex, collaborative behaviors across distributed, reconfigurable satellites. In this paper, we investigate the intersection of these two technologies as they support the development of complex, change-tolerant systems. We present an effective approach for bounding computationally independent models so that, as they transition to the architecture, capabilities-based groupings of components are relevant to the change-tolerant properties that must convey in the design solution space. The model-based engineering approach is validated via a fully functional prototype and verified by generating nontrivial multiagent systems and reusing components in subsequent systems. We build off of this research completed on the collaborative agent architecture, discuss the CE approach for the transition to architecture, and then examine how this will be applied in the reconfigurable computing community with the new National Science Foundation Center for High-Performance Reconfigurable Computing. Based on this work and extrapolating from similar efforts, the model-based approach shows promise to reduce the complexities of software evolution and increase productivity—particularly as the model libraries are populated with canonical components.     

Capturing and reusing knowledge in engineering change management: A case of automobile development

The development of complex products, such as automobiles, involves engineering changes that frequently require redesigning or altering the products. Although it has been found that efficient management of knowledge and collaboration in engineering changes is crucial for the success of new product development, extant systems for engineering changes focus mainly on storing documents related to the engineering changes or simply automating the approval processes, while the knowledge that is generated from collaboration and decision-making processes may not be captured and managed easily. This consequently limits the use of the systems by the participants in engineering change processes. This paper describes a model for knowledge management and collaboration in engineering change processes, and based on the model, builds a prototype system that demonstrates the model’s strengths. We studied a major Korean automobile company to analyze the automobile industry’s unique requirements regarding engineering changes. We also developed domain ontologies from the case to facilitate knowledge sharing in the design process. For achieving efficient retrieval and reuse of past engineering changes, we used a case-based reasoning (CBR) with a concept-based similarity measure.

FuzEmotion as a backward kansei engineering tool

Kansei engineering, also known as kansei ergonomics or emotional engineering, aims at analysing and incorporating customer s feeling and demands into product function and product design. Founded in the late 1970 s, kansei is now considered as a key consumer-oriented technology for new product development. This paper described a system called FuzEmotion for the purpose of assessing the kansei aspects of a product by considering design attributes of a product. Fuzzy logic is used to represent kansei words and process fuzzy input. The system has been successfully implemented to ascertain gender inclination of a mobile phone. Principal parameters of a mobile phone are considered, i.e., length, width, thickness, and mass. The system can inform gender inclination of a mobile phone with accuracy up to 76%. This is based on a set of 92 mobile phone samples from the five major mobile phone manufacturers.     

Requirements engineering for e-business advantage

As a means of contributing to the achievement of business advantage for companies engaging in e-business, we propose a requirements engineering framework that incorporates a business strategy dimension. We employ Jackson’s Problem Frames approach, goal modeling, and business process modeling (BPM) to achieve this. Jackson’s context diagrams, used to represent business model context, are integrated with goal models to describe the requirements of the business strategy. We leverage the paradigm of projection in both approaches as a means of simultaneously decomposing both the requirement and context parts, from an abstract business level to concrete system requirements. Our approach maintains traceability to high-level business objectives via contribution relationship links in the goal model. We integrate use of role activity diagrams to describe business processes in detail where needed. The feasibility of our approach is shown by a well-known case study taken from the literature.     

Human centered design in the air traffic control system

A review of the current air traffic control system is undertaken from the perspective of human centered design, focusing on the development of today’s system, the problems in today’s system, and the challenges going forward. Today’s system evolved around the operators in the system (mainly air traffic controllers and pilots), rather than being designed based on specific engineering analyses. This human centered focus has helped make air transportation remarkably safe, but has also made the air traffic control system somewhat inscrutable. This opaqueness of how the system operates poses significant problems for current attempts to transform the system into its “next generation” with significantly improved capacity. Research advances in human centered computing research required in order for this transformation work to proceed are discussed, specifically advances in computing the safety of complex human-integrated systems, understanding and measuring situation awareness, and visualizations of complex data.     

Metaphor, myth and mimicry: The bases of software engineering

The term software engineering has had a problematic history since its appearance in the 1960s. At first seen as a euphemism for programming, it has now come to encompass a wide range of activities. At its core lies the desire of software developers to mimic ‘real’ engineers, and claim the status of an engineering discipline. Attempts to establish such a discipline, however, confront pressing commercial demands for cheap and timely software products. This paper briefly examines some of the claims for the engineering nature of software development, before moving to argue that the term ‘engineering’ itself carries with it some unwanted baggage. This contributes to the intellectual quandary in which software development finds itself, and this is exacerbated by many writers who rely upon and propagate a mythical view of ‘engineering.’ To complicate matters further, our understanding of software development is grounded in a series of metaphors that highlight some key aspects of the field, but push other important issues into the shadows. A re‐reading of Brooks' “No Silver Bullet” paper indicates that the metaphorical bases of software development have been recognized for some time. They cannot simply be jettisoned, but perhaps they need widening to incorporate others such as Brooks' concepts of growth and nurture of software. Two examples illustrate the role played by metaphor in software development, and the paper concludes with the idea that perhaps we need to adopt a more critical stance to the ‘engineering’ roots of our endeavours*. *I should like to express my thanks to the anonymous reviewers of the first draft of this paper. Two of them offered useful advice to enhance the finished version; the third gave vent to a perfectly valid concern, that the argument as stated could have grave side effects if it was used as a point of leverage in arguments over ownership of the term ‘engineering.’ I understand this concern and the potential financial implications that prompt its expression; but in the longer term I see this exercise in clarification as a contribution to such discussions, inasmuch as it helps defuse the potency of terms such as ‘engineering.’ This revised version was published online in June 2006 with corrections to the Cover Date.     

Situated cognitive engineering for crew support in space

Space crews are in need for excellent cognitive support to perform nominal and off-nominal actions. This paper presents a coherent cognitive engineering methodology for the design of such support, which may be used to establish adequate usability, context-specific support that is integrated into astronaut’s task performance and/or electronic partners who enhance human–machine team’s resilience. It comprises (a) usability guidelines, measures and methods, (b) a general process guide that integrates task procedure design into user interface design and a software framework to implement such support and (c) theories, methods and tools to analyse, model and test future human–machine collaborations in space. In empirical studies, the knowledge base and tools for crew support are continuously being extended, refined and maintained.     

Language and Space: a two-level semantic approach based on principles of ontological engineering

An increasing number of applications for dialogue systems presuppose an ability to deal appropriately with space. Dialogues with assistance systems, intelligent mobility devices and navigation systems all commonly involve the use of spatial language. For smooth interaction, this spatial language cannot be interpreted ‘in the abstract’—it must instead be related directly to a user’s physical location, orientation, goals and needs and be embedded appropriately in a system’s interaction. This is far from straightforward. The situated interpretation of natural language concerning space, spatial relationships and spatial activities represents an unsolved challenge at this time. Despite extensive work on spatial language involving many disciplines, there are no generally accepted accounts that provide support for the kind of flexible language use observed in real human-human spatial dialogues. In this paper, I review some recent approaches to the semantics for natural language expressions concerning space in order to motivate a two-level semantic-based approach to the interpretation of spatial language. This draws on a new combination of natural language processing and principles of ontological engineering and stands as a foundation for more sophisticated and natural dialogue system behavior where spatial information is involved.     

An interactive example-driven approach to graphics recognition in engineering drawings

An interactive example-driven approach to graphics recognition in engineering drawings is proposed. The scenario is that the user first interactively provides an example of a graphic object; the system instantly learns its graphical knowledge and uses the acquired knowledge to recognize the same type of graphic objects. The proposed approach represents the graphical knowledge of an object in terms of its structural components and their syntactical relationships. We summarize four types of geometric constraints for knowledge representation, based on which we develop an algorithm for knowledge acquisition. Another algorithm for graphics recognition using the acquired graphical knowledge is also proposed, which is actually a sequential examination of these constraints. In the algorithm, we first guess the next component’s attributes (e.g., size, position and orientation) by reasoning from an earlier found component and the constraint between them, and then search for this hypothetical component in the drawing. If all of the hypothetical components are found, a graphic object of this type is recognized. For improving the system’s recognition accuracy, we develop a user feedback scheme, which can update the graphical knowledge from both positive (missing) and negative (mis-recognized) examples provided by the user for subsequent recognition. Experiments have shown that our proposed approach is both efficient and effective for recognizing various types of graphic objects in engineering drawings. This paper is an extension of our papers published in ICDAR2003 and GREC2003.     

Converting scenarios to CSP traces with Mise en Scene for requirements-based programming

The Requirements-to-Design-to-Code (R2D2C) project of NASA’s Software Engineering Laboratory is based on inferring a formal specification expressed in Communicating Sequential Processes (CSP) from system requirements supplied in the form of CSP traces. The traces, in turn, are to be derived from scenarios, a user-friendly medium used to describe the required behavior of computer systems under development. An extensive survey of the “scenario” concept and an overview of scenario-based approaches to system engineering are presented. This work, called Mise en Scene, defines a new scenario medium (scenario notation language, SNL) suitable for control-dominated systems, coupled with a two-stage process for automatic translation of scenarios to a new trace medium (trace notation language, TNL), which encompasses CSP traces. Notes on progress toward a “smart” scenario authoring tool are provided, as well as a detailed case study. This work was originally presented at the Software Engineering Workshop (SEW-31) in March 2007. It was supported by research grants from Canada’s Natural Sciences and Engineering Research Council (NSERC).     

Kharitonov’s theorem and routh criterion for stability margin of interval systems

In this paper, it is shown that the gain margin and phase margin of interval system can be determined analytically using Kharitonov’s theorem and V. Krishnamurthi’s corollary on Routh criterion without using graphical and iterative techniques. Further, it is proved that the existing results of Anderson et al. [2] on the stability of low-order interval systems using Kharitonov’s theorem are only applicable for absolute stability of the interval system and it is not applicable for relative stability of the interval systems, i.e., for phase margin. The proposed technique and stability analysis for low-order interval systems are verified with examples.     

Multi-driver agent-based traffic simulation systems for evaluating the effects of advanced driver assistance systems on road traffic accidents

A recent investigation revealed that there is a substantiated need for the development of a micro-simulation system designed for traffic safety assessment. This paper describes the development of a road traffic simulation system, which uses a ‘nanoscopic model’ of driver behaviour and an integrated analysis-evaluation system designed for traffic safety assessment. The primary focus is on estimating the effects of an advanced driver assistance system thereby reducing traffic accidents. The effectiveness and validity of the present system are demonstrated through comparison with measured traffic data. This paper also proposes algorithms embedded in a ‘driver-agent’, for recognising driver’s intentions regarding choosing steering-control modes, lateral control tasks, and the driving mood. This is because the driver assistance systems need to recognise the driver’s intention when choosing steering-control. The results of a simulation study, using the data drawn from actual driving, show that the systems would achieve a high recognition capability. As an example of how driving mood recognition applies to driver assistance systems, an advanced steering system and the adaptability to the driver’s mood, have also been presented.     

Emergence and refinement

Emergent behaviour—system behaviour not determined by the behaviours of system components when considered in isolation—is commonplace in multi-agent systems, particularly when agents adapt to environmental change. This article considers the manner in which Formal Methods may be used to authenticate the trustworthiness of such systems. Techniques are considered for capturing emergent behaviour in the system specification and then the incremental refinement method is applied to justify design decisions embodied in an implementation. To demonstrate the approach, one and two-dimensional cellular automata are studied. In particular an incremental refinement of the ‘glider’ in Conway’s Game of Life is given from its specification.     

Optimizing planned maintenance graphs for collections of engineering network sections

We consider the control problem for maintenance works on a city’s engineering networks and for planning capital repairs on a collection of network sections of various purposes.     

Real-time behavior-based robot control

Behavior-based systems form the basis of autonomous control for many robots, but there is a need to ensure these systems respond in a timely manner. Unexpected latency can adversely affect the quality of an autonomous system’s operations, which in turn can affect lives and property in the real-world. A robots ability to detect and handle external events is paramount to providing safe and dependable operation. This paper presents a concurrent version of a behavior-based system called the Real-Time Unified Behavior Framework, which establishes a responsive basis of behavior-based control that does not bind the system developer to any single behavior hierarchy. The concurrent design of the framework is based on modern software engineering principles and only specifies a functional interface for components, leaving the implementation details to the developers. In addition, the individual behaviors are executed by a real-time scheduler, guaranteeing the responsiveness of routines that are critical to the autonomous system’s safe operation. Experimental results demonstrate the ability of this approach to provide predictable temporal operation, independent of fluctuations in high-level computational loads.     

Situational method engineering: combining assembly-based and roadmap-driven approaches

Because the engineering situation of each information system development (ISD) project is different, engineering methods need to be adapted, transformed or enhanced to satisfy the specific project situation. Contributions, in the field of situational method engineering (SME), aim at providing techniques and tools allowing to construct project-specific methods instead of looking for universally applicable ones. In addition to the engineering method tailoring, necessary to fit the project situation, a customization of the engineering method for each engineer participating in the project is also required. Such a configuration allows a better understanding of the method by focusing on guidelines related to the project engineer’s daily tasks. It also increases his/her involvement in the ISD method realization. To achieve this twofold objective (ISD method tailoring and customization), we propose a framework for SME combining an assembly-based approach for project-specific method construction and a roadmap-driven approach for engineer-specific method configuration. The first step of our process provides support to build a new method that is most suitable for the current ISD project situation, whereas the second step aims at choosing the most adapted path (roadmap) to satisfy the requirements of a particular project engineer within the project-specific method. The two core elements of our SME framework are the method chunks repository and the reuse frame. The former concerns reusable method components definition and storage whereas the latter deals with the characterization of the project situation and the project engineer’s profile. In this paper we start first by presenting our SME framework and its core elements: the method chunk repository and the reuse frame. Then we show how to take advantage of them through our two-step process combining assembly-based method construction and roadmap-driven method configuration.     

Goal-driven risk assessment in requirements engineering

Risk analysis is traditionally considered a critical activity for the whole software system’s lifecycle. Risks are identified by considering technical aspects (e.g., failures of the system, unavailability of services, etc.) and handled by suitable countermeasures through a refined design. This, however, introduces the problem of reconsidering system requirements. In this paper, we propose a goal-oriented approach for analyzing risks during the requirements analysis phase. Risks are analyzed along with stakeholder interests, and then countermeasures are identified and introduced as part of the system’s requirements. This work extends the Tropos goal modeling formal framework proposing new concepts, qualitative reasoning techniques, and methodological procedures. The approach is based on a conceptual framework composed of three main layers: assets, events, and treatments. We use “loan origination process” case study to illustrate the proposal, and we present and discuss experimental results obtained from the case study.     

Requirements engineering in small and medium enterprises

Little is known about requirements engineering practices in small and medium enterprises (SMEs). This paper summarises the results of a workshop on requirements engineering held with practitioners from 10 SMEs. The current state-of-the-practice, as reported by the practitioners, differs significantly, and so do their individual problems due to contextual issues (e.g., in-house vs. contract development, type of product). The participants were presented with a set of current requirements engineering principles, techniques, methods, and tools. Important concepts were motivated by small case studies and experiments which we employed as a vehicle for technology transfer. The design of these and their results are described, as well as the practitioner’s rating of the techniques and methods.     

Systems engineering for software engineers

This paper describes how we have modified a software engineering stream within a computer science course to include broader concepts of systems engineering. We justify this inclusion by showing how many reported problems with large systems are not just software problems but relate to system issues such as hardware and operational processes. We describe what we mean by systems engineering and go on to discuss the particular course structure which we have developed. We explain, in some detail, the contents of two specific systems engineering courses (Software Intensive Systems Engineering and Critical Systems Engineering) and discuss the problems and challenges we have faced in making these changes. In the appendix, we provide details of the case studies which are used as linking themes in our courses.