Available To Promise (ATP)

What is ATP? 

Available to Promise (ATP) is method of checking the projected supply of an item at a given time. ATP provides available quantities of the requested item and delivery due dates i.e. ATP provides with information on when the item quantity will be available based on current on-hand, plus incoming supply and outgoing demand 

ATP Quantity = On-hand quantity + Supply - Demand

ATP rules determine the sources of Supply and Demand and also, specifies the time when supply is assumed to be infinite. There are two types of ATP where the ATP information is retrieved from

1. ATP Based on Collected Data: This is the basic type of ATP where calculation is based on collected data from transactional system. It can be deployed without ASCP. The main capabilities of this type of ATP are 
• Basic ATP
• Single-Level Supply Chain ATP
• Product Family ATP
• Configuration ATP
• Demand Class ATP
2. ATP Based on Planning Output: This type of ATP calculates the availability from the output of an ASCP Plan and promises delivery date based on it. This offers more advanced options
• Basic ATP
• Multi-Level Supply Chain ATP
• Product Family ATP
• Configuration ATP
• Allocated ATP
• Demand Class ATP
• End Item Substituation

How to Know Which Type of ATP is used

Type of ATP used is defined by profile option "INV: Capable to Promise". This is a site level profile option and values are 

• ATP/CTP based on Planning Output
• ATP based on collected Data

What are the Steps involved for Checking ATP 

Inputs for ATP Calculation

Following are the inputs required for calculation of ATP 

1. Item
2. Item quantity
3. Unit of Measure and
4. Request Date

Based on input information, ATP can be calculated for a single order line or for entire order. ATP results for a single order line are displayed in a separate "Availability" window. 

Output of ATP 

Following information is displayed in the "Availability" window

1. Warehouse: This is the warehouse from which the item will be shipped. If warehouse is available at order line then it is displayed. If warehouse is not available at order line, then best warehouse is picked up based on sourcing rule
2. Request Date Qty: This is the quantity that is available on Request Date
3. On-Hand Qty: Quantity that is currently available in warehouse
4. Qty Reservable: On-hand quantity that is available to be reserved against the sales order line i.e. on-hand quantity minus quantity that is already reserved
5. Available Date: This is the date on which the ordered quantity will be available. It is the request date if order quantity is available or future date i.e. date at which the requested quantity will be available 
6. Error Message: Any error that occurred during ATP calculation. Or, message when ATP is not applicable for the item
7. Substitute Item: If the requested item is not available but quantity for substitute item is available, then the substitute item will be displayed

If ASCP is not used then ATP rules must be defined to determine the sources of supply and demand which are included in calculations. Also, running the data collection plan is mandatory to summarize the supply and demand picture and ATP calculations are performed on summary tables

Important Item Attribute

ATP and ATP Components Flag determine the level of complexity while ATP calculation.

1. Check ATP: Determines if the availability date of the item in an Order is driven by material availability, resource availability or both 
2. Check ATP Components: Determines if the availability of the item i.e. promise date is dependent on the availability of its components

Define ATP Rules

ATP Rules are defined in Oracle Inventory and these Rules are used for calculating ATP details for an Order. Multiple ATP rules can be defined as per organization need and can be used independent of each other as per requirement. Each ATP rule is combination of ATP computation options, time fence options and supply & Demand options. ATP rules can't be deleted but can be modified or renamed. 

1. Consumption: Optional, either one, both or none can be selected 
• Forward: Uses the available quantities from future periods to cover a period shortage
• Backward: Uses the available quantity from prior periods to cover a period shortage
2. Accumulate Available: If backward consumption is selected this field indicates if ATP information should be calculated by carrying available quantity from one period over to the next (Accumulate)
3. Past Due Days: This field determines the number of days to be considered for determining past due demand and supply time fence days. While calculating ATP for an item, Oracle Inventory does not consider any Demand or Supply source scheduled before these dates. 
4. Infinite Supply: The Infinite supply time fence days marks the end of ATP horizon, after which inventory assumes infinite supply is available to cover for any scheduled demand. Possible list of values for this field are
• Cumulative Total Lead Time:  Cumulative Total Lead time of an item is used for determining infinite supply time fence
• Cumulative Mfg Lead Time: Cumulative Manufacturing lead time of an item is used for determining infinite supply time fence
• Total Lead Time: Total Lead time of an item is used for determining infinite supply time fence
• User Defined Time Fence: Uses the lead time provided in Days to be considered as ATP horizon
5. ATP by Demand Class: If selected then following supply sources are not available
• Internal Requisitions
• Supplier Requisitions
• Purchase Orders
• On-hand available
• Interorg Transfers
6. Demand Sources: Controls the demand sources which are to be considered while calculating ATP
7. Supply Sources: Controls the supply sources which are to be considered while calculating ATP