If the scheduled finish date of a task is later than its baseline finish date and the task is on the project’s critical path, it will naturally impacting the finish date of the project.
Step 1: Make sure baseline is set for the project plan. Choose Project ribbon > Set Baseline in Schedule group. Select Baseline in Set Baseline drop down and click OK button.
Step 2: In Gantt Chart view, change the table to Tracking and record the actual in Actual Start, Actual Finish and % complete.
Step 3: Change the table back to Entry. Insert Flag1 column. This column will be customized to indicate if the critical task has missed its original finish date.
Step 4: Select the Flag1 column. Choose Project ribbon > Custom Fields in Properties group.
Step 5: In Custom Attributes section, choose Formula button and paste the below formula
IIf([Finish Variance]>0 And [Critical]=True,True,False)
Step 6: In Calculation for tasks and group summary tasks, choose Formula button and click OK button.