Please see these details below;

IFS Applications 10 Demand Planner error "The period has already been aggregated. Create Forecast can only be run once per period"

Introduction:

From IFS Applications 10 it is only possible to run the Demand Planner ‘Create Forecast’ job once per period (which will usually be a week or a month depending on how the period versions are defined). 

The reason for this change was the introduction of the ‘Moveable Holiday’ functionality and the way in which Demand Planner computes these values.

There is often a requirement to run the Create Forecast job more than once per period when the functionality is being tested or when training is taking place.

In order to address this requirement, a change can be made to the Registry Settings of the machine that is hosting the Demand Server (which is normally a Virtual Machine). 

From IFS Applications 10 (Update 8) DP Server 6.02.xxx, it is also possible to amend the Registry Settings directly at database level.  Although the default settings are initially taken from the registry of the Demand Server virtual machine, they are then copied and maintained at database level.  As a result, this is where they will need to be changed.

Registry Setting:

The Registry Setting that needs to be updated is called ‘FixedDate’.

It will have a NULL value by default, but this can be updated to a real date with the format YYYYMMDD

The 'FixedDate' value will then be used by the Demand Server each time it runs.  In other words, the Demand Server will always 'think' that it's the Fixed Date when it looks at the historic transactions and creates the forward forecast. 

The system will display a message stating 'Warning: Running Fixed Date' in the Demand Server / Server Dashboard Log when the Fixed Date is used.

-------------------------------------------------

Note that any changes to the Registry or Database Settings should only be done by IFS Customer Services and only in the TEST or TRAINING database. 

These changes should NEVER be done in the PROD or LIVE database as the Demand Planner may not work correctly and data can be lost.

As a result, please request these changes by logging a support case/ticket with IFS Customer Services.

------------------------------------------------------------

Just wanted to save someone else time. In Cloud, you don’t need IFS to do this for you. The registry settings are available under “Supply Chain Planning  > Demand Planning > Basic Data > Demand Plan Server > select your server > Advanced Server Settings”. FixedDate is in there.  I waited for my support ticket to be answered only to learn it was there all along.