Understanding on Rule Based Availability Check (Fan Network and Chain)

HI All,

In RBA while determining location substitution procedure and product substitution procedure we go with the product list and location list.

Say for example we have product P1 P2 P3 P4 P5 and so on .and location list L1 L2 L3 L4 L5 and so on

Rule control will dictate how to traverse through the list (whether to take input as reference or just top and bottom of the list)

start from bottom or start from top or work forward from input and then back ward from input ..and so on

All I need to understand is how fan network and chain will apply on this product and location list ..what does it signifies ..????

Appreciate your help at the earliest ..!

Thanks & Regards'

Ramesh