Is it possible to start a process instance from a web application

I have the following situtation:

1 - A web portal of an organization has a feature that records customer orders;
2 - Whenever a request is received It's necessary to start an organizational process to treat the order generated;

What It's already done:
1 - The web portal already exists;
2 - We designed a process to treat the order;

Now I want do link both in a way that every order generates it's own process instance.