Periodic Costing > Concepts > Periodic Costing Uses Methods and Modes
  
Periodic Costing Uses Methods and Modes
Periodic Costing includes two costing methods and two modes.
Periodic Costing calculates the cost of items periodically and generates GL transactions according to the period costs for all costs, using one of two methods:
Weighted Average (WAVG)
WAVG considers the previous period cost and the average of the cost incurred during this period.
First in First Out (FIFO)
FIFO considers the receipt date of items for the existing inventory and assumes that the oldest (first) receipts in stock of the item are issued first.
For more information on WAVG and FIFO, refer to Costing Methods.
For modes, you can set up Periodic Costing in either of two modes:
Adjustment mode
Complete mode
The following topics explain the two modes in more detail.
Adjustment Mode
Customers who have requirements to produce financial reports based on both standard cost and Periodic Cost (WAVG or FIFO) should use the adjustment mode for Periodic Costing.
For this purpose, the system makes use of the layers concept in GL. The system posts standard cost transactions to the official layer, and it posts the periodic cost transactions to the transient and management layer once the period closes. Corporate reporting is through the official layer and local reporting is through a combination of the management and official layers.
Adjustment mode means that the operational module generates GL transactions at the standard cost at the same time as the transaction happens. The Periodic Costing calculation then revalues all of these transactions and creates adjustment GL transactions. So the GL cost set must be a standard cost set to work with Periodic Costing Adjustment Mode.
When you use adjustment mode, you have instantaneous costing data from standard costs. The system creates general ledger transactions when you create inventory transactions. It creates period cost transactions at the end of the period.
In adjustment mode, the system generates standard costing GL transactions when regular daily events occur. Periodic Costing then creates an adjustment to standard cost based on the difference between standard and calculated Periodic costs. You set Create GL Transactions to Yes in Inventory Accounting Control (36.9.2); see Setting Up Periodic Costing.
Multinational companies can use standard costing to meet their management accounting, internal audit, and corporate requirements, while also using Periodic Costing functions for legal (end of period) accounting or actual costs requirements.
See Statutory and Base Currency Calculations.
GL Transactions for Adjustment to Standard Costs
When you select the option to create an adjustment to standard cost, the system completely reverses the standard cost-based transactions in GL. It then calculates the periodic cost for the method used. The system posts standard cost transactions to the official layer. It posts the reverse of the standard cost transactions and the periodic cost transaction to the transient layer. Once the period is closed, the PC transactions are moved from the transient to the management layer.
Complete Mode
In complete mode, the system does not post any standard cost transactions. It only posts periodic inventory costs to the GL at the end of the period. As opposed to Adjustment Mode, the Complete Mode only produces one type of financial book based on periodic cost.
In this mode, you set Create GL Transactions is set to No in Inventory Accounting Control (36.9.2). In this mode, the system continues to post PO receipts transactions. This is required so that AP sub-ledger accounts always match correctly, without having to wait until the Periodic Costing close process posts to the GL.
Complete mode is less frequently in use, although in Brazil and certain other locales it may be a preferred best practice.
GL Transactions for Complete Mode
In Complete Mode, there will only be Periodic Cost based transactions calculated at the end of the period. These transactions are posted to the transient layer. Once the period is closed, the PC transactions are moved from the transient to the official layer.
Costing Methods
Two methods for periodic costing are available:
WAVG
FIFO
For WAVG, you can determine the item unit cost by analyzing initial inventory before period start as all received inventory during the calculation period, but for FIFO, item unit cost is based on how inventory is consumed. For more information, see Weighted Average (WAVG).
For FIFO, there are key differences in theoretical calculations and the QAD approach. The QAD approach approximates the theoretical calculations but considers practical issues, such as:
The number of daily transactions, which can be very large
The large number of users for which transaction sequencing can be cumbersome
Asynchronous physical receipts or issues versus data captured
Complexities when calculating production transactions
Also, when you use FIFO, for the overhead cost of RCT-PO, you set up overhead cost of the prior period using PC Unit Cost Adjustment. When the system processes RCT-PO, it reads the PC cost from prior period costset.
For FIFO, when there are multiple buckets set up for every period, you should set up overhead cost for the first bucket of prior period. For more information on FIFO, see First In, First Out (FIFO).
In the QAD solution, the system averages the unit costs by cost calculation period, by dividing total value of received goods by the total quantity received. The system maintains the quantity received by cost calculation period by consuming the inventory from the oldest periods first and then chronologically period by period up to the most recent period.
The topics within this section explain each method and provide examples in tables. In the tables, goods for sale (or quantity to issue) considers the beginning inventory and the quantities received during that period, which are the inbound receipt transactions. The different formulas to define the periodic costs are illustrated using the example shown in Formula Example.

Formula Example
 
Beginning Balance
Qty QOH
Unit Cost
Value
 
300
2
600
 
 
 
 
Receipts
Qty Received
Unit Cost
Value
May 1
200
2.2
440
May 8
300
2.3
690
May 14
200
2.5
500
Total Received
700
 
1630
 
 
 
 
Goods for Sale
1000
 
2230
 
 
 
 
Issues
Qty Issued
Unit Cost
Value
May 8
-150
 
 
May 22
-200
 
 
May 28
-400
 
 
Total Issued
-750
 
 
 
 
 
 
End Balance
QTY OH
Unit Cost
Value
 
250
 
 
Weighted Average (WAVG)
Weighted average (WAVG) considers the previous period cost and the average of the cost incurred this period. WAVG assumes that the material or production of a given kind is so intermingled that an issue cannot be made from a particular lot and cost should therefore represent an average of the entire supply. The calculation considers the previous period cost and the average of the cost incurred this period. The system looks at the Inventory and WIP Balance Report (30.5.19.2) to determine the ending balance from location detail and uses the information when determining costs in the cost calculation period when you use the WAVG method.
Average cost produces results that typically fall somewhere between results for FIFO costs. The calculation is as follows:
This period material cost = (Sum of this period (Receipt Quantity * Receipt Cost) / (this period receipt quantity)
Note: You define the period using PC Periods Maintenance (30.5.1.1).
 
Received Quantity
Unit Cost at receipt
200
2.20
300
2.30
200
2.50
This period material cost = (200 * 2.20 +300 * 2.30 + 200 * 2.50) / (200 + 300 + 200) = 2.33
The unit cost calculation is as follows:
(This period material cost * this period receipt quantity + last period Unit cost * last period item quantity balance + this period material cost adjustment) / (this period receipt quantity + last period item quantity balance)
 
Opening Inventory Balance
Last Period Unit Cost
300
2.00
This period Unit Cost = (700 * 2.33 + 300 * 2.00) / (700 + 300) = 2.23

WAVG Example
 
Beginning Balance
Qty QOH
Unit Cost
Value
 
300
2
600
 
 
 
 
Receipts
Qty Received
Unit Cost
Value
May 1
200
2.2
440
May 8
300
2.3
690
May 14
200
2.5
500
Total Received
700
2.32857
1630
 
 
 
 
Goods for Sale
1000
2.23
2230
 
 
 
 
Issues
Qty Issued
Unit Cost
Value
May 8
-150
2.23
-334.5
May 22
-200
2.23
-446
May 28
-400
2.23
-892
Total Issued
-750
2.23
-1672.5
 
 
 
 
End Balance
QTY OH
Unit Cost
Value
 
250
2.23
5575
First In, First Out (FIFO)
The First In, First Out (FIFO) method considers the receipt date of items for all existing inventory. This method assumes that the oldest (first) item in stock will be issued first. The following table provides the theoretical way that FIFO is calculated.

FIFO Theoretical Example
 
 
 
 
Beginning Balance
Qty QOH
Unit Cost
Value
 
 
300
2
600
 
 
 
 
 
 
Receipts
Qty Received
Unit Cost
Value
 
May 1
200
2.2
440
 
May 14
300
2.3
690
 
May 31
200
2.5
500
 
Total Received
700
2.33
1630
 
 
 
 
 
 
Goods for Sale
1000
 
2230
 
 
 
 
 
 
Issues
Qty Issued
Unit Cost
Value
Value Calculations
May 8
-150
 
-300
(150 * 2)
Initial inventory
May 22
-200
 
-410
(150*2 + 50*2.2)
Remaining initial inventory and receipt of 50 on May 1, etc.
May 28
-400
 
-906
(150*2.2 + 250*2.3)
Total Issued
-750
 
-710
 
 
 
 
 
 
End Balance
QTY OH
Unit Cost
Value
 
 
250
2.34
615
 
Beginning Balance
0
2
0
 
May 1
0
2.2
0
 
May 14
50
2.3
115
 
May 31
200
2.5
500
 
The ending inventory was received at two occasions’ costs:
 
Quantity
Receipt Unit Cost
50
Remaining stock received May 14
2.3
200
Remaining stock received May 31
2.5
Ending Inventory Value: 50 * 2.3 + 200 * 2.5 = 615
Unit cost: 615 / 250 = 2.46
The FIFO method provides a good indication of the balance-sheet value of ending inventory. However, in an economy with rising prices, it also increases net income because older inventory is used to value the cost of goods sold—potentially increasing the amount of taxes that a company should pay.
The following example shows the QAD FIFO solution.

FIFO QAD Solution
 
 
Beginning Balance
Qty QOH
Unit Cost
Value
 
 
300
2
600
 
 
 
 
 
 
Receipts
Qty Received
Unit Cost
Value
 
May 1
200
2.2
440
 
May 14
300
2.3
690
 
May 31
200
2.5
500
 
Total Received
Bucket 1
700
2.32857
1630
 
Goods for Sale
1000
 
2230
 
 
 
 
 
 
Issues
Qty Issued
Unit Cost
Value
Value Calculations
May 8
-150
 
-300
(150 * 2)
May 22
-200
 
-416.3
(400*2.32857)
May 28
-400
 
-931.43
(400*2.32857)
Total Issued
-750
 
-710
 
 
 
 
 
 
End Balance
QTY OH
Unit Cost
Value
 
 
250
2.32857
582.14
 
Beginning Balance
0
2
0
 
Balance Bucket 1
250
2.32857
582.14
 
The QAD FIFO solution considers buckets with a weighted average that is calculated based on all receipts and specific related costs.
In the example, the system created only one bucket. The system first calculates the weighted average of the bucket; then, consumes inventory based on FIFO principles.
Note: The smaller the buckets, the closer the QAD FIFO value approximates the theoretical FIFO value; however, it makes the system more difficult to maintain and periodic costing calculations longer. So, it is a business consideration to decide the number of buckets to define by GL calendar period. For example, having two buckets (one from May 1-15 and the other from May 16-31) causes two unit cost values (2.26 for the first bucket and 2.5 for the second bucket) to be calculated.
Reporting
You can use several reports and browses when using Periodic Costing. Numerous reports are provided, including legal reports for countries that have additional reporting requirements, such as Brazil.
General Periodic Costing reports let you see the following data:
Period costing data and its impact on the inventory value
Per-period aspects that meet legal report requirements, such as inventory movement and balance, costs per transaction, WIP balance per item and site, and so on
Inventory by account with company and item data, unit of measure, company address, and so on
Actual cost analysis of all items
For more information on reports, see Reporting Periodic Cost Data.