Prescriptive Study: Developing Design Support
5.5 Conceptualisation
5.5.2 Generating and Selecting Support Concepts
After the main functions have been selected, alternative concepts of the support are generated. Through evaluation, combination and refinement, a viable and promising concept is selected for further detailing and implementation. A review of the literature, focusing specifically on the functions of the support is useful at this stage, so as to identify means or ideas from the literature that could be used to fulfil the functions.
Key Factor
reliability of embodiment
level of unity level of
simplicity level of
clarity
+ +
+ +
support early assessment
of C, S, U
knowledge of simplicity level
quality of modification
knowledge of unity level
+
+ +
+ +
+ + + +
+ +
+ +
++
knowledge of clarity level
Key Factor
reliability of embodiment
level of unity level of
simplicity level of
clarity
+ +
+ +
support early assessment
of C, S, U
knowledge of simplicity level
quality of modification
knowledge of unity level
+
+ +
+ +
+ + + +
+ +
+ +
++
knowledge of clarity level
possible scenarios
likely scenarios
desirable scenarios
realistic scenarios
possible scenarios
likely scenarios
desirable scenarios
realistic scenarios
To generate new concepts it is important to be receptive, open and inquisitive, and let the environment trigger one’s brain cells. There is much knowledge available that can be relevant, that just needs to get linked. It is also important to be critical about one’s own concepts and to try to deliberately search for faults, potential shortcomings, uncertainties, etc., in order to generate alternative, better concepts.
It is often found that conceptualisation in product design is achieved by co- evolution: early, high-level requirements guide the generation of potential solutions, their evaluation leads to the generation of solution-specific requirements, which are then addressed by modifying the solution to add further detail, and so forth (Nidamarthi et al. 1997). In our experience, co-evolution holds true for support development as well: generation or adaptation of a particular concept for fulfilling a certain function will often lead to specific, detailed requirements related to that concept. In Appendix B pointers to useful methods can be found.
As pointed out earlier, making assumptions explicit is crucial in research and essential for developing and evaluating support. This implies that the Impact Model should be updated in every stage. The already-mentioned Checklist of Scope and Assumptions (see Appendix B.4) helps in identifying sources of possible assumptions.
Reliability Example
In the reliability example, in order to develop concepts for assessing the levels of CSU, it is necessary to define measures for these levels that can be applied with the data available in the early embodiment stage. As discussed in Chapter 4, clarity, simplicity and unity relate to components, interfaces and their configuration. Based on the literature, unity was defined as the mechanical strength of the components, for which tools are available. Simplicity was defined as the number of components and interfaces, which is relatively easy to determine. Because the literature did not provide a clear definition of clarity, other than that it depends on the clarity of the interfaces, the clarity measurement in DS-I was based on expert opinion. For obvious reasons, this is not an option for support. It is necessary to find a relevant definition of the level of clarity of an interface that can be determined in early embodiment and to find the relationship between the clarity measures of the individual interfaces and the clarity of the embodiment. To that end, information from existing work on clarity has to be combined with the original contribution from the researcher to fill in the voids in current understanding. The focus on components and interfaces lead the researcher to propose the concept of a component-interface diagram that can be derived from early engineering drawings or CAD models, assuming that a description of components, interfaces and configuration at a functional or conceptual level description is sufficient to make the measurements and thus assessments.
The PS stage thus focused on three tasks: (1) developing a component-interface diagram from the information available at the early embodiment design stage, (2) developing measures for simplicity, unity and in particular clarity, (3) developing a method for assessing the levels of CSU.
Synthesis Example
At this point we would like to introduce another (simplified) example about a researcher who becomes interested in improving the process of generating product ideas (synthesis) after hearing and reading some literature about the importance of idea generation. This example is inspired by the research presented in Appendix C.3 of this book. We will henceforth refer to this as the synthesis example. The synthesis example project focuses on PS and DS-II (research Type 6 in Figure 3.12), whereas the reliability example project had a focus on DS-I and PS (research Type 5 in Figure 3.12). The results of the RC Stage and the Review-based DS-I stage can be summarised as follows.
The researcher reviews the existing literature in depth to understand the current situation and finds several interesting empirical studies that support her idea to aid idea generation. One study showed that most designers do not consider more than a few ideas during their design process. Another study on the design processes of companies with products of poor quality showed that what these companies had in common was also that they did not consider more than a few ideas in each process.
Several other studies revealed that an increase in product quality improves customer satisfaction as well as the amount of profit. At the end of the Review- based DS-I the researcher puts the findings together in a Reference Model, a simplified version of which is shown in Figure 5.6. She decides to take the ‘number of ideas considered during design’ as the Key Factor influencing the quality of the product. High profit and customer satisfaction are taken as Success Criteria. Given the timeframe of the research project, the researcher decides to focus on increased product quality as Measurable Success Criterion. Other factors, such as cost of production, known to affect the amount of profit, are considered outside the scope of the research project. Because of its importance, cost of production is added to the Reference Model, but graphically marked as out of scope.
Based on this Reference Model, the researcher concludes that considering a large number of ideas may lead to products of high quality, although she also realises that this may require the ideas to be quite different. That is, she assumes that the values of the factors shown in the Reference Model alongside the links can be reversed, provided that a wide range of ideas is considered. Obviously, this is still only an assumption: no studies were found showing that companies that develop products of high quality do consider a large number of ideas and of a wider range during their design processes.
The researcher envisages the desired situation as one in which a support is available to help designers consider a wider range of ideas in design. This should help achieve better-quality products, which in turn should improve customer satisfaction and the amount of profit. She represents the assumptions and her line of argumentation in an Initial Impact Model (see Figure 5.7).
The researcher proceeds with a PS. After setting up a requirements list for the envisaged support, she considers various alternative concepts for supporting designers to consider a wider range of ideas. One alternative concept for providing a wide range of possible ideas is to develop a catalogue of existing product ideas that can be explored by designers (in the hope they consider these).
Figure 5.6 Reference Model for the synthesis example (simplified)
Figure 5.7 Initial Impact Model for the synthesis example (simplified)
Another concept is to provide designers with a wide range of possible ideas that are developed automatically by synthesising exhaustive combinations from a set of idea-building blocks. This concept was chosen as potentially more successful in generating a wide range of ideas, and shown as alternative A in the Impact Model in Figure 5.8. Elaborating on alternative A while taking into account the worry that designers may not consider the ideas that are generated, a third alternative was generated (Concept B in Figure 5.8). This concept not only provides a wide range of ideas but also encourages these ideas to be considered by supporting their exploration. Both concepts lead to several research questions, such as: What is a
support designers consider a wide
range of ideas
+
Success Factor customer
satisfaction
+ + +
cost of production
_
+
Measurable Success Factor
profit
+
+ +
Key Factor
quality of product
no. of ideas considered during
design [A]
[2,3]
[3,4] [5]
support designers consider a wide
range of ideas
+
Success Factor customer
satisfaction
+ + +
cost of production
_
+
Measurable Success Factor
profit
+
+ +
Key Factor
quality of product
no. of ideas considered during
design
support designers consider a wide
range of ideas
+
Success Factor customer
satisfaction
+ + +
cost of production
_
+
Measurable Success Factor
profit
+
+ +
Key Factor
quality of product
no. of ideas considered during
design [A]
[2,3]
[3,4] [5]
Success Factor customer
satisfaction
+ + +
cost of production Measurable _
Success Factor
profit
+ +
quality of product
[2,3]
[3,4] [5]
__
Key
Factor no. of ideas considered during
design [1]
Success Factor customer
satisfaction
+ + +
cost of production Measurable _
Success Factor
profit
+ +
quality of product
[2,3]
[3,4] [5]
__
Key
Factor no. of ideas considered during
design
__ [1]
Key
Factor no. of ideas considered during
design [1]
suitable set of building blocks? What are methods for exhaustively combining these? What form should exploration take? How should the ideas be presented so that the user has an overview?
Figure 5.8 Impact Model with alternative support concepts for the synthesis example
The answers to these questions will have consequences for the support, resulting in additional functions. This enforces further refinement of the Impact Model. Take for example the above question about how the ideas should be presented. This was raised because the fulfilment of the function ‘provide wide range of ideas’ was considered necessary but not sufficient to encourage designers to consider a larger number of ideas. The range should be presented such that it allows an overview, thus introducing an additional function: ‘provide overview of ideas’. Both functions might have particular effects that are not yet represented in the Impact Model. Such effects thus lead to additional factors and links, namely those that are influenced by these functions. The first function, for example, affects a factor that can be called
‘quality of overview’; the second function affects the factor ‘range of ideas’. These factors, together, are responsible for influencing the ‘number of ideas considered’
in the original Intended Impact Model and should be added to the model (not illustrated here).