# Revisiting Problem-Solution Co-Evolution in the Context of Team Conceptual Design Activity
## 1 Introduction
Namely, when designers conceptualise, they transform the initial and often ill-defined design problem into a clear description of a concept solution, thus ensuring a more certain design work in the subsequent stages [25; 26]. The conceptual design stage demands substantial exploration and offers the most scope for striking improvements in return [27]. This is probably the reason why most of the design literature encourages team activity whenever there is a need for idea generation, or solution finding, evaluation, and refining [14; 15; 28; 29; 30]. Consequently, team activity is most desirable during tasks, such as defining product specification, searching for working principles, concept generation and evaluation, selection and refinement of concept solutions, and design reviews; that is, throughout the conceptual design phase. Indeed, the descriptive research studies confirm that not only does the majority of engineering designers in modern industrial practice work as part of a team [31; 32], but the creative conceptual design tasks, such as idea generation or concept selection, are often performed exclusively as team activities [33; 34]. Such a collaborative approach to framing design problems and developing solutions to these problems is believed to be the driver of creativity and innovativeness in the early product development stages [24]. It is thus no surprise that a large portion of experimental design research related to team activity has been related directly to the conceptual design stage [35]. Taking into account the state-of-the-art in design research and the introduced context of designing in teams, one can provoke the following question: Are the conventional prescriptive models of design and their descriptive counterparts accurate in describing the fine-grain problem-solving patterns appearing during team conceptual design activities? Namely, as shown hereafter, there exists a gap in the literature when it comes to fine-grain process modelling of team design activities. The presented study aims to address the proposed research question and bridge the research gap by revisiting some of the well-established assumptions that regard ASE as drivers of problem-solving and problem-solution co-evolution in the context of team design activity. As such, the study aims to investigate the validity of both the conventional problem-solving as an underlying process of designing, as well as the complementary viewpoint of problems and solutions evolving together. The new insights could potentially help design researchers to align the conceptualisation of ASE within the design models as well as to adapt the design methods to better suit the needs of collaborative design. Three sets of hypotheses have been proposed hereafter, in order to address the relevance of current models for fine-grain investigation of team design activity. The first hypothesis set concerns the relationship between performing ASE and teams' focus on exploring either the design problem or the design solutions. Namely, the prescriptive design research approaches, which inherit the problem-solving interpretation of ASE, have related the notion of analysis predominately to the problem space, where it envelops understanding, decomposition, and formulation of problem-related entities, primarily the design requirements (see, e.g., [36; 37]). A few of the descriptive approaches accept the problem-related interpretation of analysis (e.g., [38; 39]), whereas the others challenge it by favouring the relation of performing analysis and exploring the solution space instead (e.g., [40; 41; 42]). Therefore, the assumption that analysis is primarily related to the problem space exploration, as it is often instructed by the prescriptive design literature, should be revisited in the context of team designing. Namely, this assumption goes beyond simple counting of instances where teams perform problem analysis versus instances where they perform solution analysis (this has already been addressed in one of the previous studies; please consult [43]).