As sketched in Phase II of Figure 2 above, computer-generated
alternatives and their realization should evolve in successive cycles
where results from experimental tests are fed back to problem
formulation (3), in the form of updated models and heuristics. When
several alternative formulations are required, a rank of feasible
solutions with increasing values of the objective f may be generated
through integer cuts.30 In any case, successive cycles
should desirably result in an optimal alternative, which meets all
product specifications and integrate the consumer assessment. Most
heuristic rules have a linear formulation, however, property and process
functions are likely to be non-linear, so problems in the form of (3)
will be MINLP problems, as it is illustrated in the case study.
In summary, a general methodological approach is presented here for the
design of formulated products, in which a fuzzy measure analysis for the
consumer assessment, along with heuristics and property models
incorporation for the product realization phase, are used to guide the
selection of formulations that solve the original design problem, using
the reformulations of cosmetic emulsions as case studies.