"Yes," Leo smiled. "An index of 1.0 means 'exactly average.' Below 1.0 is low season. Above 1.0 is high season." "Now you can predict next year," Leo said. "First, forecast your total sales for next year using a simple trend—say, you expect 10% growth because you're adding outdoor seating."
She implemented the system. The following summer, she ordered 80 gallons of chocolate fudge instead of 40, and she didn't run out once. In winter, she launched a small hot cocoa and cookie menu (index 0.34 meant low volume, so she kept it simple). She stopped wasting money on full staff in January. how to calculate seasonal variation
"Finally," Leo said, "multiply that 'average season' by each Seasonal Index." "Yes," Leo smiled