The business motivation behind interacting business processes stems from business to business:

The business motivation behind interacting business processes stems from
value systems, which represent collaborations between the value chains of
multiple companies. These high-level collaborations are realized by interacting
business processes, each of which is run by one company in a business to
business process scenario. This section studies interactions between business
processes performed by different companies.
For the sake of concreteness, this section uses an example from the area of
order processing, described as follows. A buyer orders goods from a reseller,
who acts as an intermediary. The reseller sends a respective product request to
a manufacturer, who delivers to product to the buyer. In addition, the reseller
asks a payment organization to take care of the billing.
The manufacturer then ships the products to the buyer.
The value system shown on a high level of abstraction is detailled
Note that for each value chain in the value system shown
there is a participant in the business-to-business collaboration,
detailling its internal structure and its contribution to the collaboration.
There are many interesting issues to study: how do we make sure that the
business-to-business process created by putting together a set of existing business
processes really fulfils its requirements? Structural criteria, for instance,
absence from deadlock, need to be valid for these processes.
The problem is aggravated by the fact that internal business processes are
an important asset of enterprises. Therefore, few enterprises like to expose
their internal processes to the outside world. This means that
the properties of the overall business-to-business collaboration cannot be based on the actual
detailed local processes run by the enterprises, but rather on the externally
visible behaviour and the associated models to represent it.