Which of the following is the reason that software is delivered late ?

A. Changing customer requirements that are not reflected in schedule changes
B. Technical difficulties that could not have been foreseen in advance
C. Human difficulties that could not have been foreseen in advance
D. All of the mentioned
✅ The correct answer is option D.

The expected value for the estimation variable (size), S, can be computed as a weighted average of the optimistic(Sopt), most likely (Sm), and pessimistic (Spess) estimates given as___________________?

A. EV = (Sopt + 4Sm + Spess)/4
B. EV = (Sopt + 4Sm + Spess)/6
C. EV = (Sopt + 2Sm + Spess)/6
D. EV = (Sopt + 2Sm + Spess)/4
✅ The correct answer is option B.
Explanation: This assumes that there is a very small probability that the actual size result will fall outside the optimistic or pessimistic values.