Fill in the blanks and show formulas. Draw the activity network flow diagram and find a Critical Path. What is the expected project duration (Minimum Duration)? Draw the activity network flow diagram and find a Critical Path. Slack = Late Start (LS) - Early Start (ES) What is the expected project duration (Minimum Duration)? Slack = Late Finish (LF) - Early Finish (EF) On a critical path, we do not have a slack.