Unable to edit the project plan

If we implemented a project plan some time back,  lets say we want to tweak a new plan that is forward looking  - is that possible ? 

The project wording in conformio that is unchangeable  seems to suggest that after an initial implementation project there is no ability to record or manage other discrete projects using the conformio wizard..  
An example project item might be to enhance our monitoring capability

Is it the case, that instead  of a future  project plan/s as such , the way forward for all mini projects  is to capture all tasks as part of corrective actions etc ?   i.e. the conformio project planning module is purely for initial implementation ? i.e not to cover post implementation exercises ? 

Look forward to your response, so I can advise business senior management and the auditor accordingly