Material reconciliation is the easiest Job, there are three things involved in it.
Material ordered by company
Material consumed by company
Material in stock after consumption.
You can calculate the above quantities as per design, estimation etc methods.
you need to verify the physical stock is correct or not and if it is less then you need to take actual physical stock for reconciliation.
The difference between actual and theoretical consumption is nothing but a your reconciliation variation, most are interested in that figure only.