How do fashion designers forcast fashion and how many season ahead do they do it for?

me: How do fashion designers forcast fashion and how many season ahead do they do it for?
I just wondered how fashion designers etc do this. I am curious as I hear about it all the time but wanted more information.

Answers and Views:

Answer by steven m
The try to set the Fashion rather than forecast it

If they know a warehouse load of free blue cloth is going to be available next year — good chance they will be trying to get everyone wearing blue

They also watch what films will be coming to the cinemas – these can influence fashion and taste too.

Answer by GGem
they are the ones who create the fashion, they design the trends. it’s high street brands and people in advertising who do the forecasting, based on what the lovely designers give them.

they normally design a two seasons ahead. but they only come out on the catwalks one season before.

so the spring/summer collection will come out in winter. but the designers will be on the next autumn/winter collection.