An objective is considered to be in progress until it is marked as 'finished' by the line manager.
Finished means you no longer want to observe that objective and that it can be dismissed. It doesn't necessarily mean the objective was completed successfully by the appraisee. In addition to marking it as 'finished', the line manager may provide a final assessment rating for the objective, depending on the template used.
Appraisees should make their own final assessment using the progress update feature if they want to.