Unit Of Measure(UOM) in Oracle Applications Inventory

UOM Tables Relationship

Units Of Measure Form

Form: INVSDUOM.fmb

Table: MTL_UNITS_OF_MEASURE

MTL_UNITS_OF_MEASURE is the definition table for both the 25-character and the 3-character units of measure.
The base_uom_flag indicates if the unit of measure is the primary unit of measure for the uom_class.
Oracle Inventory uses this table keep track of the units of measure than can be used to transact an item. This table is also used by Oracle Purchasing, and Oracle Order Entry/Shipping.

Unit Of Measure Classes

Form:INVSDOCL.fmb
Table: MTL_UOM_CLASSES
MTL_UOM_CLASSES is the definition of the unit of measure classes. A class is a category to which units of measure are assigned.
Oracle Inventory defines this table, and it is used by Oracle Purchasing and Oracle Order Entry/Shipping.

Unit Of Measure Conversions

Form: INVSDOUC.fmb
Table1: MTL_UOM_CONVERSIONS
MTL_UOM_CONVERSIONS stores conversion rates between non-base units of measure and their base unit. The non-base units of measure are stored in the table.
The default_conversion_flag indicates that the conversion being defined is
1) associated with a specific item and
2) the conversion between units of measure has already been defined as a standard conversion with the same conversion rate.

Table2: MTL_UOM_CLASS_CONVERSIONS
MTL_UOM_CLASS_CONVERSIONS is where conversions between base units of measure are defined for an item. A base unit of measure is the primary unit for a class.

Intra-Class VS Inter-Class

Under Intra-class And Standard Tab,User can only define conversation within  same class;
Under Inter-class tab, you can define conversation between different base uom which in different UOM class;

Lot Inter-Class Unit of Measure Conversions

Form:INVSDLUC.fmb
Table:MTL_LOT_UOM_CLASS_CONVERSIONS
Conversion between the Base UOMs of two different UOM classes specific to an Item and Lot (Organization Specific).

Unit of Measure conversions in Transactions

Each Transaction involves three units of measure -

§  Transaction UOM

§  Primary UOM

§  Secondary UOM

It should be clarified that although there could be three units of measures on a transaction, the onhand quantity is always stored in the primary UoM.

o  The simplest case of UOM Conversion in Transactions is - All the Three UOMs belong to the same UOM Class (assume that none of them are base UOM). This case requires three conversions -

1.      Convert Transaction UOM to Base UOM

2.      Convert Base UOM to Primary UOM

3.      Convert Base UOM to Secondary UOM

o  Most Complex Case of UOM Conversion in Transactions is- Each of the Three UOMs belong to different UOM Classes –

• Transaction UOM belongs to UOM Class T
• Primary UOM belongs to UOM Class P
• Secondary UOM belongs to UOM Class S

For such a case, it requires five conversions -

1.      Convert Transaction UOM in Class T to Base UOMin Class T

2.      Convert Base UOM in Class T to Base UOM in ClassP

3.      Convert Base UOM in Class P to Primary UOM inClass P (this gives Primary UOM)

4.      Convert Base UOM in Class P to Base UOM in Base UOM in Class S

5.     ConvertBase UOM in Class S to  Secondary UOM inClass S (this gives Secondary UOM)

From the Two cases, it is evident that a conversion from Transaction UOM to Secondary UOM requires a minimum of two conversions (in simplest case)to a maximum of 4 conversions (in complex case) and after each conversion, the result might potentially be rounded to inventory rounding (5 digits).