A procurement offi cer fi nds that the delivery time for a specifi c item is never less than 5 days. The worst case scenario is that it takes 30 days for the item to arrive. A delivery lead time of 10 days is more frequent than any other.

a. Calculate the expected delivery time.

b. What estimate would you give for its variance?

c. What factors would you take into account when deciding the amount of time to be allowed for in the project plan for delivery of the item?