A seasonal curve is a description of how a value (such as sales) varies in percent over a year. When entered as a seasonal curve, the total yearly value is distributed by percentage over a number of periods. The number of periods in the year can vary, for example monthly or quarterly.
Seasonal curves are identified by a three-digit number and can be defined for each calendar year. This means that a seasonal curve ID entered for item groups or product groups cannot be changed from one year to another, even if the curve itself changes.
When seasonal shares are entered and updated, the sum of the percentages for all forecast periods must be 100% in order for the entries and changes to be approved.
Seasonal curves are entered in 'Seasonal Curve. Open' (CRS915). It can also be connected to item groups or product groups in 'Item Group. Open' (CRS025) and 'Product Group. Open' (CRS035).
Seasonal curves are used in many different contexts in M3, but primarily for budgeting and forecasting. They are used to make calculations as reliable as possible by taking into consideration periodic variations.
If advance payment of bonus/commission is used, a seasonal curve is important since the percentage used to calculate the bonus is based on the expected yearly bonus.
A highly seasonal product is outboard motors for recreational boats. Assume 80% of a company's sales are made between April and September, while 12% of sales are made from January to March.
In this case the expected yearly bonus for a salesperson calculated in March based on the previous quarter will naturally be incorrect. Using a seasonal curve that takes into account the wide variation in sales of this product will provide a more reliable basis for calculating the bonus.