Which of the following audit procedures would be most effective in determining if purchasing requirements have been updated for changes in production techniques?

(a) Recalculate parts needed based on current production estimates and the MRP for the revised production techniques. Compare these needs with purchase orders generated from the system for the same period.

(b) Develop test data to input into the LAN and compare purchase orders generated from test data with purchase orders generated from production data.

(c) Use generalized audit software to develop a report of excess inventory. Compare the inventory with current production volume.

(d) Select a sample of production estimates and MRPs for several periods and trace them into the system to determine that input is accurate.

A company maintains production data on personal computers, connected by a local area network (LAN), and uses the data to generate automatic purchases via electronic data interchange.
Purchases are made from authorized vendors based on production plans for the next month and on an authorized materials requirements plan (MRP) which identifies the parts needed for each unit of production.