Subtasks are created via  File    New    Task   within the parent task. The only differences to creating single tasks are:

• Subtask data fields may be defined to be completely new data fields, but they may also be selected from a list of parent data fields and eventually existing peer data fields.
• Subtasks may be created when the parent has status initial by the creator of the parent (pre-defining a workflow), or by the contractor of the parent task when the parent task is 'running', i.e. it has been started and not yet reached a final status (accepted or cancelled).