Material
The IE is concerned with the delivery and flow of material throughout the plant, often the plant has evolved as the company has.

Lot size

To allow the manufacturer to stay flexible the production lot sizes should be minimalized. This will only be economical after the reduction of machine set-ups have been achieved.

Since inventory is capital that cannot be converted until finished and purchased by a consumer, it should be kept to a minimal. Inventories not only tie up capital but if the customer requests a change then the inventory runs the risk of becoming obsolete.

Quality

The quality of the material can affect all parts of the system. Poor quality material often introduces excessive amounts of rework into each of the processes. A typical job for an IE would be to work with the quality department to set up a Quality Management system QMS.

The amount of maintenance that the machine is going to require is a variable that must be considered. Another issue about maintenance is whether or not the staff on hand will need to be retrained.