Overview
"Backflushing" is a term used to describe the function of automatically issuing Component Items from Inventory to a Work Order, rather than manually entering Work Order Issue transactions. The quantity backflushed is calculated using the Work Order Component Item Quantity Per and the Quantity Completed at an operation (for components with Backflush Policy = First Operation), or at the time of Work Order Receipt (for components with Backflush Policy = Last Operation).
NOTE: The Backflush Policy is defined by default on the Inventory Commodity Code associated with the component item. However, it can be overridden and defined on the Inventory Item Master for any component.
A Backflush Policy must first be selected to have an Item backflush on a Work Order, either as Last Operation or First Operation (which actually means 'Not Last Operation'). The Item must be identified as a Backflush Item on the Inventory Commodity Code associated with the Inventory Item Master, or as an override on the Inventory Item Master.
Additionally, the Inventory of the Item to be backflushed must be in a location where the Location ID has 'Backflush Indicator' and the 'Available for Picking' fields set to True. When a component item has a Backflush Policy of 'No Backflushing' that component must be manually issued using the Work Order Component Issue process. Therefore, on any given Work Order, it is possible to have some component items backflush while others are required to be issued manually.
When a Work Order Demand is created by the Extract Components process, the system will check to see if the Component Item is a Backflush Item. If it is, then the Backflush Policy on the Work Order Demand is set according to the Backflush Policy on the Inventory Commodity Code (or the override value on the Inventory Item Master).
NOTE: Component Items that are serial controlled can be backflushed. Component items that are lot controlled will be backflushed in lot number sequence.
Application
EXAMPLE When the Component Item is of low cost, or when the time and effort to count and manually issue to the Work Order is costlier than the value of the Item. For example, hardware or bench stock.
Setup Location ID for Backflushing
Inventory Location ID must be indicated to be a Backflush Location
NOTE: When Inventory is added an Inventory Item By Location record is created or updated. The values for Backflush Location and Available for Picking are set from this Inventory Location Id value. Location IDs from which Component Items will be backflushed should have the Backflush Location and Default Available for Picking Indicators set.
Navigation
Inventory Location IDs
Field
Backflush Location: Checkbox should be True
Default Available for Picking: Checkbox should be True
Setup Components for Backflush
Backflush Last Operation
Summary
For those Work Order Component Item Demands that have a Backflush Policy of 'Last Operation', when a Work Order Receipt is processed, the system will search for the first Inventory Item By Location record associated with the Component where the Backflush Indicator and Available for Picking indicators are both true, and will automatically create a Work Order Component Issue Transaction, decrementing the Location quantity by the Work Order demand quantity. If the calculated backflush transaction is for more than the Inventory Item By Location contains, another search will be performed to find the 'next' Inventory Item By Location record, until the entire quantity required is processed. If no other eligible locations exist, the Item will not fully backflush.
NOTE An Inventory Item By Location Quantity is not permitted to be negative.
Navigation
Inventory Commodity Code > Misc Tab > Backflush Policy must be set to Last Operation or First Operation
OR
Inventory Item Master > Misc CC Overrides Tab > Backflush Policy checkbox must be set to false, then either Last Operation or First Operation must be selected
Backflush Policy: Options are Last Operation, First Operation (which actually means Not Last Operation), or No Backflush. Set to Last Operation or First Operation.
Last Operation: Component Items assigned with this value are backflushed (issued) from Inventory to the Work Order ONLY when the Work Order is received. Backflushing is NOT performed for Operation Completions.
Process - Backflush Last Operation
When a Work Order Receipt is processed, Work Order Component Items designated as Backflush Last Operation will be backflushed.
NOTE When the Work Order Receipt Reversal is processed, the backflushed Work Order Component Items will be reversed to the Backflush Inventory.
Summary
For those Work Order Item Demands with a Backflush Policy of ‘First Operation’, the system will identify the Work Order Operation, then the Work Center, when a quantity is completed at an Operation, EXCEPT the Last Operation on the Routing, since quantities are not completed at the Last Operation. The Issue Location ID value on the Work Center will be used to find the Inventory By Item Location records from which to backflush. When an operation Quantity Completion is processed, a Work Order Component Issue Transaction decrementing the Location Quantity, is generated.
NOTE An Inventory Item By Location On-Hand Quantity cannot be negative.
If the Backflush Quantity is greater than the Available Quantity in a Location ID/Location Number, the system will search for the next eligible location. If no other eligible locations exist, the Component Item will not fully backflush.
Backflush Policy: Options are First Operation (meaning not Last Operation), Last Operation, or No Backflush. Set to First Operation.
First Operation: Items assigned with this value are backflushed (issued) from Inventory to the Work Order when Quantity Completions are processed for any operation in the routing EXCEPT the Final Operation. If Inventory is available and Standard Operations are used, quantity completions at the Operation will trigger the backflush.
NOTE When the Work Order Operation Quantity Booking Reversal is processed, the backflushed Work Order Component Items will be reversed to the Backflush Inventory.
IMPORTANT When the 'Operation Number' is specified for a Work Order Component, the 'Backflush Policy' field is ignored, the system backflushes the Work Order Component during Time and Quantity Booking completion for that Operation,
Backflush at Specified Operation Setup
Summary
First Operation Backflush requires that Engineering Bill of Material Master Component Item records have a Bill of Material Override Entry created for each Component designated as Backflush First Operation. This record specifies the Demand Line (user-defined), Work Center, Quantity, and the Process Number of the Operation at which the backflush of the Component is to be generated when an Operation Quantity is booked.
Navigation
Engineering BOM Master > BOM Overrides Tab
Fields
Demand Line: This number is a unique identifier for a specific Component quantity being backflushed. If multiple Demand Lines are created for a Component, the part can be backflushed at various operations, splitting the total quantity to be issued as necessary.
Work Center: The Work Center used due to this override. This works with the Process Number identified below so that the Backflush Function will be triggered when the combined Work Center and process are used.
Quantity Per: The quantity of the Component Item to be backflushed at this Work Center/Process combination. It may or may not be the entire quantity of this Item. Other amounts may be used upon the First Operation or other overrides.
Lead Time Offset: Not used in Backflushing. The number of days after the Work Order Start Date that the Component on this override record will be needed. This is used for Material Requirements Planning.
Process Number: The Process Number assigned to the operation.
Process - Backflush at Specified Operation
When a Work Order Operation Quantity completion is processed for the specified Operation, and designated Work Order Component Items will be backflushed.
Specifying the Work Center - Issue Location
Summary
When First Operation Backflush is selected, a backflush-enabled Location ID is associated with the Work Center. This Location ID may be a Warehouse Location ID or it may be a location on the Shop Floor to which Component Inventory is moved from the Warehouse to the Work Center Location with a Location to Location Transfer.
Navigation
Manufacturing Work Center
Field
Issue Location ID: Select the Issue Location ID associated with the Work Center. Component Items that are identified as Backflush First Operation and which are identified in a Bill of Material Override record will be backflushed from this location.
SEE ALSO
Work Order Overview
Work Order Operation
Inventory Location IDs
Inventory Commodity Code Misc Tab
Inventory Item Master Misc CC Override tab
Engineering BOM Master
Work Order Receipt
Work Order Receipt Reversal
Time and Quantity Booking
Time and Quantity Booking Reversal
Location to Location Transfer
