Execute (Business-Process) according-to (Contract)

[jinnerbichler]

Provided that a user has the necessary rights, he or she will be able to start the execution of a business process with the help of the NIMBLE platform. This may be the purchase of some goods including the use of a specific delivery service or the use of some third party services that may be available on the platform.

[jinnerbichler]

Needs to be split into smaller issues.