Symptom
Environment
 SAP SuccessFactors Workforce Analytics
Resolution
Suppose that a Production site contains "data as of" April 30, 2010. External Hires figures for the months of 2010 so far are as follows:
 January  11
 February  13
 March  17
 April  9
Assume that the following results are shown in Calendar Year. (Fiscal Year works the same way if you substitute JulyOctober for JanuaryApril.)
External Hires/Recruits for 2010, Actual: 50. When a year is not yet complete, the total for the year to date (YTD) is used.
External Hires/Recruits for 2010, Annualised: 150. In principle, the annualised figure is what would be reached at the end of the year if the remaining months had the same average total as the months so far.
Explicitly put: Annualised total =

[YTD total] * 12 / [months so far] or

[YTD total] / [months so far] * 12.
It is fairly easy to annualise a YTD figure mentally, depending on which month is current.

In the above case: four months is 1/3 of a year, so the total is multiplied by 3.

If there were data up to May: five months is 5/12 of a year, so the total would be multiplied by 12/5 or 2.4.

If there were data up to October: ten months is 10/12 or 5/6 of a year, so the total would be multiplied by 6/5 or 1.2.
Annualisation only applies correctly to measures which accumulate over time, like Hires, Terminations or Absence Days.

Averaged measures such as Average Headcount should not be annualised, because the average for a year is not necessarily larger than the average headcount for a single month.

Startofperiod/endofperiod measures should not be annualised, because the total at the start/end of a year is the same as the total at the start/end of the first/last month.

Calculated measures may divide a cumulative measure by an averaged or "ofperiod" measure. For instance, Termination Rate = Terminations / Average Headcount. Such measures generally can be, and are, usefully annualised.
Keywords
Annualized data, Actual data, Year to date, YTD, WFA data, annualized measure , KBA , LODSFWFAWA , Workforce Anaytics , How To