The continuous integration and verification of components is essential in distributed design processes. Identifying the optimal integration and verification frequency, however, can be challenging due to the complexity of product development. Especially the effect of human decision-making in partially isolated development scenarios is difficult to consider. Thus, we performed an experimental study based on the following three steps: first, an extension of the existing parameter design framework, which is used to conduct experiments under laboratory conditions, in which human subjects solve quantitative surrogate design tasks. Second, a series of experiments in which 32 subjects divided into groups of two solved 229 parameter design tasks with a varying integration and verification frequency. And, third, a statistical analysis of the results with respect to development time, coupling strength and process costs. According to our results, development time can be reduced by up to 71%, if the integration and verification frequency is doubled. If process costs are also considered, the optimal frequency can be subject to a conflict of goals between reducing development time and minimising process cost.

This paper reports on a study characterizing design processes and the potential of design spaces through measuring the information entropy of empirical data derived from protocol studies. The sequential segments in a protocol analysis can be related to each other by examining their semantic content producing a design session's linkograph, which defines the design space for a design session. From a linkograph, it is possible to compute the probabilities of the connectivity of each segment for its forelinks and its backlinks, together with the probabilities of distance among links. A linkograph's entropy is a measure of the information in the design session. It is claimed that the entropy of the linkograph measures the potential of the design space being generated as the design proceeds chronologically. We present an approach to the automated construction of linkographs by connecting segments using the lexical database WordNet and measure its entropy. A case study of two design sessions with different characteristics was conducted, one considered more productive and creative, the other more pragmatic. Those segments with high entropy and those associated with high rates of change of entropy are analyzed. The creative session has a higher linkograph entropy. This result indicates the potential of using entropy to characterize a design process.

To complement studies on design sketching within particular phases of design processes in specific design domains, this paper analyzes descriptions of design processes given by designers from a wide variety of fields. This research forms part of a wider project on comparisons across design domains and draws attention to the many types and properties of sketches in different contexts. Further, it focuses on the multiple roles that sketching can take in idea generation, as well as in reasoning and communicating design ideas. In particular this paper examines how the different types and roles of sketches can be more or less formal and how this can lead to misunderstandings.

The goal of this paper is to reexamine assumptions about sketch-based interfaces for modeling in the context of designers' needs and practices. Research questions examine (a) the type of sketch support and (b) the timing of support. Both concepts try to determine when, what, why and how to augment design processes in a way that is useful to designers. Two experiments (one in architecture and one in product design) based on ergonomics theory are conducted and intend to question some of these assumptions. The Port Zeeland experiment examines how 20 novices perceive and copy a blurred architectural sketch, which provides clues for a sketch interpretation system. The “Tragere” experiment studies how 12 professional product designers, some of whom are “idea generators” and others “idea pursuers,” perceive, recognize, and handle a design sketch. The results take a designer's point of view in assessing the timing and value of sketch assistance in product design. The quantitative data analysis provides rich clues about when, why and how product sketches should be supported. The paper explores the strategies developed by designers to perceive and recognize graphical content and discusses the generation of three-dimensional volumes, the univocity state between sketches and three-dimensional models, and the treatment of features in freehand sketches. The paper concludes with observations on the timing and value of support, as first integrated in NEMo, a tool for early stage architectural design, and then in PEPS3, an early stage framework for product design.

This paper presents a formal analysis of design process dynamics. Such a formal analysis is a prerequisite to come to a formal theory of design and for the development of automated support for the dynamics of design processes. The analysis was geared toward the identification of dynamic design properties at different levels of aggregation. This approach is specifically suitable for component-based design processes. A complicating factor for supporting the design process is that not only the generic properties of design must be specified, but also the language chosen should be rich enough to allow specification of complex properties of the system under design. This requires a language rich enough to operate at these different levels. The Temporal Trace Language used in this paper is suitable for that. The paper shows that the analysis at the level of a design process as a whole and at subprocesses thereof is precise enough to allow for automatic simulation. Simulation allows the modeler to manipulate the specifications of the system under design to better understand the interlevel relationships in his design. The approach is illustrated by an example.

The article is an extended version of the verbal summary presented at the concluding lunch of the workshop on “Computing Futures in Engineering Design.” In the paper, the first person is used to differentiate my observations or reactions from the summaries of the speakers' presentations. The common themes that emerge during the workshop are: the need to set the discipline-specific context before computational tools are used; the incompatibilities between point tools that hinder their use; the paramount importance of teamwork; and the need to understand and treat design as a social process.