This paper presents two selection strategies for the process of establishin
g a structural design support system. The distinct difference between the s
trategies is the point of time when the decision maker participates in the
design process. The first strategy is called the preselection strategy in w
hich the designer tries to grasp the intention or preference of the decisio
n maker at an early stage of the design, and the second one is called the p
ost-selection strategy in which the designer prepares all design informatio
n as much as possible, and then the decision maker selects the final design
solution.
Based on these two strategies, the shared and essential processes of the st
ructural design support system will be explicated in advance, and then the
characteristics of these two strategies will be compared. The crucial parts
of the structural design support system are common design process that is
shared in the two strategies and the alternative based design approach. The
common design process means the basic sequences of the design process, suc
h as problem specification, concept design, preliminary design and selectio
n of the final design solution, that are used conventionally in the general
design process. These design processes are carried out with the screened r
egion of the design alternatives, which is efficient and effective for the
selection of the final design solution. With these concepts, the structural
design support system especially the grid-like type structures will be exa
mined and the usefulness of our design methodology will be confirmed.