1 For example, the disorder sickle cell anaemia is caused by a mutation in the gene that instructs the building of a protein called haemoglobin. 2  This causes the red blood cells to become an abnormal, rigid, sickle shape. 3  However, in African populations, having this mutation also protects against malaria.
Optimistic time - generally the shortest time in which the activity can be completed. It is common practice to specify optimistic times to be three standard deviations from the mean so that there is approximately a 1% chance that the activity will be completed within the optimistic time.
Sure enough, it is 31 months, because you cannot complete your project before 31 months, and this is the duration of the critical path. Hence, the critical path is the shortest duration in which you can complete the project. So, you see, both definitions are the same. We can conclude that the critical path is the sequence of activities from start to end, and it has the largest duration among all paths in a network diagram.