Engineering design thinking combines concepts from heterogeneous sources like personal experience, colleagues, digital and hardcopy media. Despite this challenge, modes of thinking across levels of abstraction through multi-dimensional (spatial) representations are widely neglected in digital support systems. This paper aims to summarize lessons learned through years of experience with software tools that augment this visio-spatial conceptual thinking. This work cuts across disciplines to provide a needed, coherent starting point for other researchers to examine complex outstanding issues on a class of promising support tools which have yet to gain widespread popularity. Three studies are used to provide specific examples across design phases, from conceptual design to embodiment. Each study also focuses on an exemplar of diagrammatic software: the University of Cambridge Design Rationale editor (DRed), the Institute for Human Machine Cognition's (IHMC) CmapTools and the Open University's Compendium hypermedia tool. This synthesis reiterates how hypermedia diagrams provide many unique, valuable functions while indicating important practical boundaries and limitations. Future research proposed includes: a need to build more diagrammatic literacy into engineering practice, the need for more detailed studies with experts in industry and specific directions for refining the hypermedia diagram software interfaces.@en

There is strong evidence of the importance of good interaction design to intuitive use of products. However, the underlying issue is that designers get little support in adequately representing, analysing and comparing design and user information. This paper proposes a new data modelling approach for designers, which in four distinct stages enables to assess and compare designers and users' understanding and usage of everyday products. The preliminary results indicate that it can contribute to the design of more inclusive products but its usefulness in industry is yet to be properly evaluated.@en

This paper addresses the general issue of software tool support for designers, helping them to structure, to communicate and to document activities of generation, evaluation and decision. Here the focus is on detailed consideration of desired and undesired behavioural relationships among elements of complex design artefacts and with end users. This is an area that has recently been under discussion by proponents and critics of Affordance Based Design methods. Our solution approach is to extend an existing graph based software tool for design rationale capture that has been in widespread use in an international aerospace company for several years. We are integrating its Issue Based Information System (IBIS) based design argumentation with hierarchical Functional Analysis Diagrams (FAD), a form of Concept Map. The resulting software is being tested by practical application on pilot projects in the company, and initial experiences have been very favourable. The new graph element types, bidirectional relationship types between graphs, and supporting navigational facilities are described. Their use is illustrated by example of an integrated hierarchical FAD and assembly geometry model of a gas turbine engine.@en

Engineers use many "cognitive technologies" to bridge the gap between human cognitive limits and the requirements of complex, distributed, asynchronous and information-intense cooperative work. This paper examines the value of narrative in engineering work to improve the design of emerging diagram-based software tools for sensemaking and information navigation. These have been studied and even adopted by some aerospace organizations but they are not yet common. In some cases, these aim to replace more traditional, narrative documents, like textual reports, because graphs reflect better the hyperlinked, non-linear structures in both engineered systems and information repositories. It is critical, however, to determine what is lost and what is gained by that transition. This paper presents a case study of teams at an aerospace company as they begin regular use of Design Rationale editor (DRed) diagramming software. The engineers were observed and interviewed over several weeks. Results, structured and analysed using DRed and the cognitive dimensions framework, suggested that diagrams are a better way to build and organize work incrementally while narrative structure is valuable in verifying completeness of work and initially guiding users around documents. Further work will involve more detailed study and modification of DRed to exploit the value of narrative.@en

Graph representations are emerging to replace more traditional narrative forms of knowledge capture. These seem to be a better fit for work with modern hyperlinked, non-linear computerized systems and design problems. The old forms, however, possessed important characteristics for effective knowledge capture. It is not exactly clear what is lost and gained in the transition. This paper explores narrative theories and examines them using the cognitive dimensions framework. A review of literature finds that deliberately constructed narrative structure is key to affording meaningful experience of representations. This suggests flaws in current documentation practice. Proposed concepts situate many new questions that will require further study.@en

Longer lifecycles and a shifting industrial focus from simple product delivery to through-life support have increased the need to retain organisational knowledge for the duration of product lifecycles and beyond. This fragmentation of work across time and organizations buries organizational understanding of design processes and of the underpinning design rationale in many disparate representations. Further, existing report-based documentary practices tend to omit key information which could compromise an engineer's ability to comprehend and reuse this information in addition to requiring significant additional authoring work. Emerging approaches to documentation are discussed and compared as cognitive technologies in a snowmobile drive shaft example. One design episode is assisted by interactively documenting decisions in an IBIS-based tool whose output forms the record. Another is passively documented via an activity-modelling approach and media-enhanced records. This work provides examples of situating discussions about engineering design documentation practices and describes improvements for further development and testing of both the activity-modelling and media-enhanced records and the IBIS-based approaches.@en

DRed is a graphical software tool for design rationale capture that, despite essentially still being a research prototype, has proved robust and useful enough gradually to achieve widespread use in an international aerospace company. The main areas of application up until now have been: (1) in the early stages of design; (2) in the root cause analysis and design of solutions to problems occurring while a product is in service. In order to lay out and navigate freely large interlinked rationales across multiple charts, DRed uses a simple bidirectional hyperlinking approach known as tunnel linking. In this paper we suggest that if it could be made easy for users to create bidirectional hyperlinks between DRed elements and selected locations in a range of external document types, then this might support the capture not just of the rationale, but of a unified, easily navigable information space covering the specification, rationale, calculations, design tasks and the emerging product definition. The objective of this research was to devise a practical way of implementing such a facility, then to explore how integrated design information spaces captured in this way might be structured, and to assess the feasibility of their capture as the design proceeds. To be successful, this will require extending the routine use of DRed from the conceptual into the embodiment design phase. Thus the case study in this paper focuses on the embodiment design of a simple mechanical transmission.@en