Ethical issues in engineering design - 3TU.Centre for Ethics and ...

Ethical issues in engineering design
For Simon the main characteristics of an ill-structured problem are that the
solution space is not well-defined and that there is no criterion to test different
solutions and decide which is best. Cross gives the following characteristics of illstructured
problems:
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‘1. There is no definite formulation of the problem.
2. Any problem formulation may embody inconsistencies.
3. Formulations of the problem are solution-dependent.
4. Proposing solutions is a means to understanding the problem.
5. There is no definitive solution to the problem.’ [Cross, 1989, 11-12]
Some design methods require that engineers formulate the requirements and
solutions separately and independently, but this is impossible if design problems
are ill-structured. In a redesign of an existing design it might be possible to
formulate most of the requirements at the start of the design process but this is
not a definition of the requirements independent of the solution. The solution
space is, in these cases, limited because a redesign is made; certain features of
the product will remain the same. Other design problems aiming at designing a
completely new product are very ill-structured and only some vague
requirements can be formulated at the start of the design process. So design
problems can be more or less ill-structured.
An example of an ill-structured problem is the following. In the mid nineteen
nineties substitutes were sought for replacing CFCs as coolants in refrigerators,
because CFCs damage the ozone layer [Van de Poel, 1998 and 2001]. Two
alternatives were considered: HFC 134a and hydrocarbons, both have their
advantages and their disadvantages. Hydrocarbons are for example flammable
and existing refrigerator design needed to be changed if hydrocarbons were
used. HFC134a has a long atmospheric lifetime and if released would therefore
still damage the environment, although to a lesser extent than CFCs. There were
different operationalisations available for the environmental, health and safety
criteria. Both proposed solutions scored differently under different
operationalisations of the criteria. There was no solution that was best under all
operationalisations. No definite criterion was available to say which solution was
the better one. This example shows that even for the seemingly simple case of
looking for a substitute coolant in existing refrigerator design, there are features
of the problem that make it ill-structured.
In cases where a design problem is an ill-structured problem, there may be
more than one solution; each of these solutions can be valid. Engineers, in this
case, have to make a choice: it is not the case that the requirements will lead to
just one solution. At the start of a design process, there may not even be a clear
and unambiguous set of requirements. During the design process it may be
proved that there is no solution to the ill-structured problem. In some cases it