A material backflush refers to a special type of material issue to a shop order. Normally, materials are issued to a shop order one item at a time based on actual usage. The actual usage can then be compared to the standard quantity required to determine material variances. However, single-issue transactions can be time-intensive and may not be necessary for low-cost, high-volume items where the variance is negligible. In these situations, a backflush transaction can save time, but still capture the usage of material on a shop order.

A material backflush transaction issues material to a shop order automatically when a shop order receipt is entered. The issue quantity is based on the component quantity required and the ratio of the shop order quantity received to the quantity ordered. For instance, if a shop order for 100 printed circuit boards requires 200 transistors, a shop order receipt for 50 printed circuit boards would prompt a backflush of 100 transistors (50 received/100 ordered * 200 required).

The backflush location is based on the default location for the operation work center. If a default location is not specified for the work center, the backflush location is based on the default location of the bill-of-material component. For example, if a component is assigned to an operation on the Assembly work center and the default Assembly location in the Work Center Master is A001, the default backflush location is A001. If a default location is not specified for the Assembly work center, the backflush location is based on the component’s default location in the Item Master.

When the shop order receipt is entered from the Inventory menu, Catalyst allows the backflush quantity for backflush items to be modified in the Backflush Confirmation screen. The Backflush Confirmation screen can be used to adjust backflush quantities based on actual usage and offers a more rapid entry of issue transactions relative to the single-issue transaction. The primary disadvantage of backflush transactions involves the timing of the transaction. When using the backflush, the issue transaction does not occur until the shop order receipt is entered. This means that material will still show as available in inventory until the shop order receipt has been entered. For situations where cycle times are long or real-time updates are required, the single-issue transaction may be the better option.

The components on a shop order can be a mix of both backflush and non-backflush. An item can be designated as backflush on the Item Master, Product Configuration Master, and Shop Order Master. The backflush flag in the Item Master serves as a default setting when the item is selected as a child item for a product configuration. When a shop order is created, the backflush flag from the product configuration is copied to the shop order. The backflush flag can be changed for any product configuration or shop order. The Backflush Confirmation screen will only display bill-of-material items that have the backflush flag set on the shop order regardless of the setting on the Item Master or Product Configuration Master.