Create custom workflow and ensure, that steps can be skipped in assignment

This is a custom workflow that should be set as default workflow for a customer.

It will have about 3-4 additional workflow steps.

It must be ensured that:

• for all workflow steps
  • the user is notified at assingment
  • the next user in the workflow and the PM are notified, when a workflow step is finished. The notification mail should list the segments changed in the previous step
• if a workflow step in the chain is not assigned, but the overnext or over-overnext steps etc. are assigned, the next assigned workflow step is triggered and the mails etc. are send and the not used workflow steps are simply skipped.