Oracle SOA Process for orders management

Question

This is about Oracle Oracle SOA 12c & BPEL Process

Actually, I work in project which allows the management of customer orders, each order passes through a seem of states. The project consisting of two parts :

1. Frontend/Backend application witch allow users to manage orders (create, change order state, ...)
2. Oracle SOA project witch contains different process

My objective is create new Oracle SOA Process (BPEL) in order to manage orders states:

Order states

Workflow :

1. After the creation of new order in the application Frontend/Backend, a new instance of Oracle BPEL process must be launched with the state : UNCONFIRMED
2. After each change of the created order state, the Oracle BPEL launched process (linked to the order) must change the state.

I note that many orders can be launched in the same time, so each process must be linked with a single order.

Questions :

How can I implement this Oracle Process ? with which component can I represent order states ? How can I link a created Order with an instance of Process ? with which mechanism can I change the state of process (linked with order)

Thanks