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Former Member
Jun 04, 2013 at 03:51 PM

# Number of Periods per Seasonal Cycle

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Dear DP Statistics Experts,

I have a very basic question

Scenario:

I have 4 years of historical demand calendar month wise

For a given Product (which is my selection ID on which forecast is being executed)

Every March-April and Oct-Nov each year, I have higher than average demand

Every Jun-July each year I have a lower than average demand

I know this highs and lows are because of certain events of rejoice and gloom resp and not really outliers.

I now create a forecast profile with a seasonal time series model. For reasoning sakes les use seasonal linear regression model 35

I use last 48 months of History and I generate forecast for next 24 months.

We are now in June 2013.

There is a parameter in the univariate profile > Model Parameters called PERIODS that expects a value of Number of Periods per Seasonal Cycle.

Given the above information what value should I enter here

A) 2

B) 4

B) 16

C) 12

D) 36

E) Some other Value

F) Ask the Client.. well he doesn't care or know either

G) Don't bother: Test each of these, get ok from the client and bill the client for the time taken

Assume that I am executing my statistical forecast in monthly periodicity with past periods = 48 and future periods = 24 on Product as a selection criteria.

I am not using Seasonal Planning in DP.. I don't know what is in there. This is standard APO DP.

The F1 help says this. Owing to my poor English language skills, I am unable to understand what this means esp. the one in bold below

### Number of Periods per Seasonal Cycle

Specifies the number of periods (for example, months) in a season.

### Procedure

If you are using a seasonal model (forecast strategies 30, 31, 35 and 54) or
a seasonal trend model (forecast strategies 40 and 41), or if the system is to
carry out a seasonal test (forecast strategies 52, 53 and 55), enter the number
of periods that make up a season.

### Dependencies

The period is specified by the planning buckets profile you enter in the
master forecast profile.

Thanks

BORAT