The potential benefits of modular design over conventional design include e
conomies of scale, increased feasibility of product/component change, incre
ased product variety, and reduced order lead-time. The benefits of modular
design have not gone unnoticed, and it is becoming evident that companies a
re increasingly seeking to use this modular approach. Important research is
sues in the area of design with modules center around the central theme of
selecting modules to satisfy customer requirements. However, while modular
product design would appear to be an attractive proposition, little work ha
s been done on these research issues, particularly for the relatively commo
n design environment where modules may be available from one or more geogra
phically dispersed sources, and where data concerning the modules may be in
a multitude of databases scattered across the globe. Under these circumsta
nces, it becomes necessary: to search through the databases using a network
, such as the Internet, for feasible subsets of the set of candidate module
s. Such a search call be difficult due to the heavily constrained environme
nt that encompasses much design activity. This paper addresses these issues
by proposing a design with modules algebra and new constrained crossover a
nd constrained mutation operators that aim to permit an evolutional approac
h to operate effectively in such an environment, and thus to produce a popu
lation of feasible designs that aim to maximize (or minimize) a given objec
tive function. The implementation of this approach is described with an exa
mple of personal computer design, where the designer is remote from the dat
abases and communication is carried out over the Internet. Some results on
the convergence of the approach are shown.