Troubleshooting 101: ScheduleOrder ScheduleOrderLines findInventory  getATP

Resolving The Problem

Yantra's Availability Logic can be split into 3 layers
OrderManagement Layer > Promise Layer > InventoryLayer

ScheduleOrderLines >
ScheduleOrder > findInventory > getATP
getPossibleSchedules >

Troubleshooting Steps
1. Use GetATP to isolate the problem.
This will confirm available Supply by SupplyTypes and Demands by Demand Types.
Any common user errors like mismatched UOM's ProductClass etc will be exposed by this results.

For e.g., in one case we got

Supply=ONHand=20,000

Demand=OpenOrder = 476
Demand=BackOrder = 50
Demand=StockOpenOrder.ex = 450
Demand=NFBackOrder = 50
Demand=Allocated = 200
Total Demand=1226

Problem is NOT with Inventory Layer.
Next Check PromiseLayer

2. Try different setting changes in the FindInventory api.
Using DemandTypes, FulfillmentTypes, dateranges etc.
Document Scenarios where Inventory is found and Scenarios where Inventory is NOT found.
In this case,
FindInventory gives No Result if 'Blank' DemandType is passed
does give Result if 'OpenOrder' DemandType is passed

In your InventoryConsiderations Screen
(ParticipantModelling(DEFAULT)>Applications>InventorySynchronization>Invento ryTypes&Considerations)
Check and make sure you have accurately matched your Demand and Supply Types.
In this case, we found that there was a deviation from Factory Setup and RSRV_ORDR and RESERVED where not matched with any Supply Type. (Also Checked the Code and found out that Blank DemandType is interpreted as RSRV_ORDER, This is a bug and will be fixed in 5.5, Blank Demand Type should be interpreted as whatever is set in ProcessType>Details>Inventory>DemandTypeForSchedule='Scheduled')

3. Also check the Demand Type Screen or Table
In this case DemandType table for Scheduled was flagged as Non-Committed as opposed to Promised (FactoryDefault)
The Committed Level (Released/Promised/Non-Committed) is very important in deceiding which demands will be knocked off against Supply.
The settings here control the Promised/Allocated and PriorityFlags in the InventoryDemandType Table

4. The above steps should bring to light any inconsistencies in the data setup that result in inconsistencies in the PromiseLayer behavior.

If the results in this layer are consistent but you still have problems in the Order Management Layer,
then the problem should be with factors like Scheduling Rules, BackOrderReprocess Interval, ATP Horizon and AdvNotificationTime etc.
Troubleshooting steps will be added here later.