How can I get a high percentage of accuracy in the forecasting process while you have not any historical data?

 When you generate a best fit forecast, the system compares actual sales order growth rate or when sales history has a significant seasonal component. The product is mature and has no trend over the long run, but a significant 

dear Mohamed,

         after wishing good day i want to thank you for your effective answer.

and i appreciate to send me more links  about forecasting ways  and i hope to share our experience 

and i can help you if you need any thing about call center industry

thanks in advance :)

You can do one of the following:1- benchmark your business model with others and try to ask your peers working in other companies. It works sometimes.2- you can use the "Reverse Forcast". Its when you start from the final product or service need in the industry & start building an imaginary senario based on real market factors. There are other ways I'm sure you can find if you read more about "Operations Management". Regards, Wish this helps. :)