The first step in materials wastage
analysis is to quantify standard quantity and type of direct materials needed
for each work item. The actual materials consumed for each work-item can be
complied from the material issues and return notes transacted between
supervisors and stockholders. In case of materials delivered directly to the
construction sites by the supplier, such as ready-mix concrete from site
batching plant or fabricated steel for reinforcement from the site steel yard,
or aggregate from a crusher, the supplier's delivery note along with the
material's return note (if any) can be used to determine the quantity consumed
for a given work-item. These issue slips and delivery notes, when
consolidated from the start to completion of the work-item/activity, can give
the quantities of materials consumed. The difference between the standard
materials requirement and the materials actually consumed indicates the excess
(if any) from the accepted materials wastage standard prepared at the time of
estimation.
Materials usage
variance = Standard acceptable materials wastage - Actual
materials wastage.
