User and design requirements and production of evidence: using incident analysis data to (1) inform user scenarios and bow ties,and (2) generate user and design requirements

This paper reports on an innovative human–machine interaction methodology adopted to assess the case, role and requirements for a new ground collision awareness technology. Specifically, this paper reports on the analysis of ground collision incident data and the subsequent advancement of user scenarios and bow-ties based on this data analysis, for the purpose of generating preliminary user and design requirements for this technology. In so doing, the requirements elicitation and validation methods used in this research are framed from an epistemological perspective. Accordingly, the particular methods adopted are presented and discussed in terms of concepts of evidence, bearing witness and the distinction between facts and values. As such, this paper promotes thinking about evidence-based design practices. Overall, this evidence-based approach aims to improve the development of scenarios and associated problem solving around technology cases, user requirements and user interface design features. The proposed method is useful in terms of bridging the gap from data analysis to design, and validating design decisions. In this regard, it is argued that the generation of user scenarios based on the analysis of incident data (i.e. data coding and statistical analysis), and the reframing of such scenarios in terms of bow-ties for the purpose of requirements/design envisionment, extends existing scenario-based design approaches. Although the use of bow-ties is not new, the advancement of bow-ties from data-driven scenarios is. Specifically, the bow-tie method was applied in a design context, to support problem solving around design decisions, as opposed to formal risk analysis.     

A Representational Framework for Scenarios of System Use

Scenarios are becoming widely used in three areas of system development: software engineering, human–computer interaction (HCI), and organisational process design. There are many reasons to use scenarios during system design. The one usually advanced in support of the practice is to aid the processes of validating the developers’ understanding of the customers’ or users’ work practices, organisational goals and structures, and system requirements. All three areas identified above deal with these processes, and not surprisingly this has given rise to a profusion of scenario-based practices and representations. Yet there has been little analysis of why scenarios should be useful, let alone whether they are. Only by having such a framework for understanding what scenarios are, and what they are for, can we begin to evaluate different scenario approaches in specific development contexts. This paper is a contribution toward such a framework. We lay out a space of representational possibilities for scenarios and enumerate a set of values or criteria that are important for different uses of scenarios. We then summarise several salient representations drawn from the software engineering, HCI, and organisational process design communities to clarify how these representational choices contribute to or detract from the goals of the respective practices. Finally, we discuss how scenario representations from one area of design may be useful in others, and we discuss the relationship between these representations and other significant early-design and requirements engineering practices.     

A design process based on a model combining scenarios with goalsand functions

While promising approaches to early system design using scenarios have been proposed, no design process is available that guides scenario-based design. We present a model that combines scenarios both with functions and goals. Functions are required to make the desired behavior of some scenario happen in order to achieve one or more goals. Using this model, we propose a systematic and concrete design process that is both model-driven and data-driven. Our design process supports the transition from the current to a new system and guides the design of a new system. In addition, this process makes it possible to detect a certain kind of redundancy and to improve both completeness and understandability of the resulting design. We have applied our approach in real-world projects, and our experience suggests the utility of this approach     

Scenario-based analysis of software architecture

Despite advances in clarifying high level design needs, analyzing a system's ability to meet desired quality criteria is still difficult. The authors propose using scenarios to make analysis more straightforward. In their case study report, they analyze lessons learned with this approach. They developed the Software Architecture Analysis Method, an approach that uses scenarios to gain information about a system's ability to meet desired quality attributes. Scenarios are brief narratives of expected or anticipated system uses from both user and developer views and they provide a look at how the system satisfies quality attributes in various use contexts     

Scenarios and the HCI-SE design problem

Diaper's critical review of Carrol's book ‘Making Use’ raises a number of interesting issues about how to set about the design of interactive systems. In particular Diaper poses an issue that has long dogged the area of Human–Computer Interaction and Software Engineering (HCI-SE), namely how to deal with the formality required by the SE side and the sensitivity to context required by the HCI side. In this paper, we report on the experience of using scenario-based design and reflect on the effectiveness of the approach. This work fits into a broader context concerned with understanding exactly what the HCI-SE design problem is and now it might be best conceptualised.     

Toward a discipline of scenario‐based architectural engineering

Software architecture analysis is a cost‐effective means of controlling risk and maintaining system quality throughout the processes of software design, development and maintenance. This paper presents a sequence of steps that maps architectural quality goals into scenarios that measure the goals, mechanisms that realize the scenarios and analytic models that measure the results. This mapping ensures that design decisions and their rationale are documented in such a fashion that they can be systematically explored, varied, and potentially traded off against each other. As systems evolve, the analytic models can be used to assess the impact of architectural changes, relative to the system's changing quality goals. Although scenarios have been extensively used in software design to understand the ways in which a system meets its operational requirements, there has been little systematic use of scenarios to support analysis, particularly analysis of a software architecture's quality attributes: modifiability, portability, extensibility, security, availability, and so forth. In this paper we present a unified approach to using scenarios to support both the design, analysis and maintenance of software architectures, and examples from large‐scale software development projects where we have applied the approach. We also present a tool, called Brie, that aids in: scenario capture, mapping scenarios to software architectures, and the association of analytic models with particular portions of architectures. The approach that we have devised, and that Brie supports, is a foundation for a discipline of architectural engineering. Architectural engineering is an iterative method of design, analysis and maintenance where design decisions are motivated by scenarios, and are supported by documented analyses.     

Exploring how children use their hands to think: an embodied interactional analysis

In order to better understand how to design hands-on child-computer interaction, we explore how different styles of interaction facilitate children's thinking while they use their hands to manipulate objects. We present an exploratory study of children solving a spatial puzzle task. We investigate how the affordances of physical, graphical and tangible interfaces may facilitate the development of thinking skills including mental visualisation, problem space exploration and collaboration. We utilise the theory of complementary actions taken from embodied cognition to develop a video coding methodology that allows us to classify behavioural activity and make inferences about thinking skills development. Our findings indicated that the combination of direct hands-on input style with audio-visual feedback facilitated by the tangible user interface enabled a dynamic task completion strategy, which supports the development of mental skills with a slight time cost. The mouse and graphical user interface supported a trial and error approach, which may limit skills development. The physical cardboard puzzle enabled effective task completion but provided less support for social interaction and problem space exploration. We conclude with design recommendations.     

基于场景模型的DDS架构一体化舰船任务系统测试

以数据分发服务(data-distribution service, DDS)为基础架构的新型一体化舰船任务系统在研发模式、结构和应用方面具有特殊特点, 使得其测试相当具有挑战. 基于模型的测试(model-based testing, MBT)是工业系统测试的一种有效方法. 然而, 对于类舰船任务系统, 由于其自身的...     

Scenario-based robust optimization of a water supply system under risk of facility failure

In this paper, we propose a scenario-based robust optimization model for the design of a water supply system considering the risk of facility failure, which is represented as an uncertainty set generated by a finite set of scenarios. New facilities are planned to be built to hedge against the possible failure of existing system facilities that would potentially damage the capacity of the system to meet given user demands. The goal is to build facilities that are both cost-effective and make the system robust. The system robustness is defined as the ability to satisfy user demands for every data realization in the uncertainty set. The proposed model is shown to be equivalent to a large-scale mixed-integer linear program that is solved by a Benders decomposition algorithm. Computational results demonstrate the efficiency of the proposed algorithm, and show that substantial improvement in system robustness can be achieved with minimal increase in system cost.     

Analysing interactive devices based on information resource constraints

Analysis of the usability of an interactive system requires both an understanding of how the system is to be used and a means of assessing the system against that understanding. Such analytic assessments are particularly important in safety-critical systems as latent vulnerabilities may exist which have negative consequences only in certain circumstances. Many existing approaches to assessment use tasks or scenarios to provide explicit representation of their understanding of use. These normative user behaviours have the advantage that they clarify assumptions about how the system will be used but have the disadvantage that they may exclude many plausible deviations from these norms. Assessments of how a design fails to support these user behaviours can be a matter of judgement based on individual experience rather than evidence. We present a systematic formal method for analysing interactive systems that is based on constraints rather than prescribed behaviour. These constraints capture precise assumptions about what information resources are used to perform action. These resources may either reside in the system itself or be external to the system. The approach is applied to two different medical device designs, comparing two infusion pumps currently in common use in hospitals. Comparison of the two devices is based on these resource assumptions to assess consistency of interaction within the design of each device.     

基于感知控制的场景界面设计方法

在普适环境下,计算环境的复杂性使普通用户不易通过预定义的操作来控制系统的状态,致使用户界面设计不能正确反映系统 的特征。为此,提出一种基于感知控制的场景设计方法。该方法利用感知控制理论对使用场景进行分析,导出用户意图控制的对象及策 略,并在此基础上重新设计使用场景,从用户任务的角度出发,使所得到的界面满足用户感知控制的需要。通过案例分析证明该方法的有效性。     

A MORF-Vision Method for Strategic Creation of IoT Solution Opportunities

With the rise of Internet of Things (IoT), companies are now facing new challenges such as diverse consumer demands and shorter lifecycle of products and services. Even in big companies, they may have to “extract” new products every six months or less. Nonetheless, shorter lifecycle is never a waiver for poor user satisfaction. Common to the companies that survived such disruptive changes is that they emphasized the user experience (UX) as one of the most important elements of their strategy. This explains why most product innovation processes such as user-centered design or design thinking emphasize so much on “empathizing.” Developing a new product or service from scratch, however, is challenging especially when the underlying technology is new to people. The aim of this study is to develop a systematic process for creating opportunities from the UX perspective. This study suggests opportunity-creation process by adopting an “abductive” design thinking approach: (1) future envisioning and (2) opportunity identification and analysis. A new method called MORF-Vision (Morphological Future Envisioning) was developed to generate prospective scenarios that can be used in phase (2) to identify potential opportunities. An experiment showed that the MORF-Vision method is helpful to create opportunities in various business domains.     

An Integrated Approach to Designing and Evaluating Collaborative Applications and Infrastructures

Collaborative systems include both general infrastructures and specific applications for supporting collaboration. Because of the relative newness and complexity of these systems, it has been unclear what approach should be used to design and evaluate them. Based on the lessons learned from our work and that of others on collaborative systems, we have derived an integrated approach to researching collaborative applications and infrastructures. The approach can be described as a sequence of steps: We decompose the functionality of collaboration systems into smaller functions that can be researched more-or-less independently. For each of these functions, we adopt general (system-independent) principles regarding the design and implementation of the function, identify collaboration scenarios at multiple levels of abstraction, identify requirements based on the scenarios, adopt an interaction model to meet the requirements, realize the interaction model as a concrete user interface, develop a logical architecture of the system, identify a physical architecture for placing the logical components in a distributed system, develop infrastructure abstractions, use the abstractions to implement applications, and perform lab studies, field experiments, and simulations to evaluate the infrastructure and applications. As in other models with multiple phases, feedback from subsequent phases is used to modify the results from the previous phases. In this paper, we describe, illustrate and motivate this research plan.     

Enhancing problem frames with scenarios and histories in UML-based software development

Abstract: Problem frames are an approach to requirements modelling that is gaining increasing attention and popularity, as it addresses the essential activity of understanding and describing the problem to be solved before undertaking the actual development phases. This paper reports a study concerning the possibility of enhancing the problem frames methodology with concepts derived from requirements modelling techniques based on scenarios and histories. The goal of this research is to make problem frames even more appealing to software developers, who are generally familiar with the ideas underlying scenario-based modelling. The results presented here are encouraging: a well-known problem, often used to illustrate problem frames (the sluice gate control), was studied with the help of scenarios, modelled by means of histories. Scenarios were also employed to support the merging of subproblems, for addressing the frame concern issues and for supporting design models. In all these activities the proposed approach proved helpful.     

An Assumption-based Truth Maintenance System in Active Aid for UNIX Users

This paper deals with the problem of assigning meaning to the interaction of a user with a command-driven system such as UNIX. This research is part of the construction of an active intelligent help system that monitors users in order to offer spontaneous help when they are facing problems. In order to ensure this, the help system must build and maintain a model of the user. We describe a mechanism that is used by the user modelling component of such a help system. This mechanism makes explicit assumptions about the user which account for different hypotheses about what the user is actually thinking at every stage of the interaction. The consistency of these assumptions is managed by an Assumption-based Truth Maintenance System (ATMS). The selection between a number of different user models is based on the information which is extracted from the feedback that UNIX provides in response to user actions. This revised version was published online in August 2006 with corrections to the Cover Date.