Modelling (pre-)Design Activities With a Multi-Stakeholder Perspective - Principia Designae: Pre-Design, Design, and Post-Design - page 179

mapped against the extended FBS model, looking for correspondences and eventual
discrepancies between its prescriptive procedure and the processes described in the
previous section of this paper. Then, the collected discrepancies have been analysed
in detail. As a result, several criticalities emerged, mostly related to a lack of
support of IDIM for some analysis and decision steps that were substantially left
to the intuition of the designer. Based on those results, a number of suggestions
about possible improvements of the IDIM have been produced.
Besides, a more typical use of the extended model is the investigation of a design
activity through a protocol analysis; in this case, the model is used as a reference to
codify the object of the design discourse (in terms of the types of variables
involved) and the related transformations (as classified by the different processes).
Examples of this kind of applications have been published in Cascini et al. ( 2013 ) ,
where the analysis deals with an innovation project with Whirlpool Europe
concerning the reduction of water and energy consumption of a washing machine,
and in Cascini and Montagna ( 2014 ) where the case study refers to a brainstorming
session aiming at the definition of the specification for a new production line, within
an Italian company operating in the aseptic filling sector.
Two reference tables can be used to guide the application of a coding scheme
based on the extended FBS model: the first (Table 12.1 ) collects the elementary
statements cast by each actor (e.g., in a co-design brainstorming session) and
associates to each statement the involved variable(s). The second table (as in
Table 12.2 ) recognizes the evolution of the thinking process through the trans-
formations applied to the design variables, and hence classifies the type of process
according to the definitions provided in the previous sections.

12.4.6 Illustrative Example

Just with the purpose of clarifying the logic of the proposed model, some hypo-
thetical reflections within the design of a kettle are here analysed. For the sake of
simplicity, the multi-stakeholder perspective is here omitted. In general, customers
provide several unstructured external needs such as reduced heating time, no
maintenance, transportability of the device, volume capacity in order to make tea
for four people, etc. These different needs feed the Need Identification step, in
particular:
• Process I: uses N e provided by customer to produce N i variables such as “avoid
formation of deposit” or “avoid impairing the following usages”.
• Process II: transforms N i into R i variables such as “subsequent usages do not
create variations of the boiling time, as well as in the chemical/physical or
organoleptic features of water”.

Indeed, the designer progressively attributes a metric and a target value to each
R i ; eventually (through the synthesis process V and/or by choosing a subset of R i in
the process IX) the expected requirements Re i

are expressed by means of