In plant engineering, all products are unique. Nevertheless, it
should be possible to find and reuse as many repeat parts as
possible. Existing search tools in PDM systems are not suitable
for this purpose, since they are too uneconomical in terms of data
maintenance in view of the small quantities of plant products, or
they are originally designed for retrieving individual parts, but not
building structures. This paper proposes the approach of per-
forming repeated searches on the basis of similar building struc-
tures and combines concepts of fuzzy searches with the traversal
of product structures for this purpose.