DWDM has been widely used by telecommunication operators

in most cases

a critical failure in machine disk

take OA failure for example

would definitely suffer tons of losses in their business

thus it is an optimum choice to substitute spare parts for those which are actually out of order. However

fault location

in some cases

is lack of corresponding spare parts

but has related substitutions from other manufacturers

hence force

we demonstrate the issue that how to take good advantage of the existing resources in order to recover our business as quickly as possible.