Hello Sunil,
Did you read F1 help for the field 'Construction Type'?
It says,
Construction type material of the object
Material number under which pieces of equipment of the same construction are grouped.
This way the equipment/ functional location can be referred to the particular material number & the bill of material created for that material will be applicable to those equipment/ functional location. This way the requirement of maintaining the BOM for individual equipment/ functional location will be minimized.
It is also useful at the time of finding the replacement equipment,
Also go through SAP help,
SAP Library - Customer Service (CS)
construction type (SAP Library - Glossary)
Mangesh S