The successful combination of aesthetic and engineering specifications is a long-standing issue.
We started considering the spectacle-frame functionality and derived the high-level formulation linking aesthetic and engineering specifications.
This paper lies in between the previous approaches since its purpose is the description of a strategy to formalise the relations among aesthetic and engineering specifications and whose validities are not affected by the product variability.
Apart from fulfilling technical specifications, aesthetic design is furthermore one of the crucial factors determining the allure of almost any product (perhaps those destined for outer space are an exception), but especially a consumer product.
The only reason digital photo frames haven't totally taken off is because they tend to be fugly affairs, the tech manufacturers that market them being far more concerned with the technical specifications of the unit that its aesthetic appeal.
The intention was not to identify a specific set of problems or technological requirements, as would occur in a formal design specification, but instead to capture in a more general way the users' "beliefs and desires, their aesthetic preferences and cultural concerns" ([ 9], page 25).
Specifications are constraints.
The specifications are off.
