A perpetual inventory system should be established under the control of someone other than the storekeepers. The system should include quantities and values for each item of raw material.
Total inventory value per the perpetual records should be agreed to the general ledger at reasonable intervals.
When physical counts are taken, they should be compared to the perpetual records. Where differences occur, they should be investigated. If the perpetual records are in error they should be adjusted.
Controls should be established over obsolescence of stored materials.