Chapter 3, Problem 23P

a)

Summary Introduction

To determine:The probability of completing the project in 17 months.

Introduction:

The activity times of various tasks in a PERT project network are assumed to follow a probability distribution. For calculating the expected times and standard deviation, the parameters required are the following:

• Optimistic time: This is the time denoted by “a”, which is the best possible or in other words, the quickest time in which an activity can be completed, assuming that everything goes as per plan.
• Pessimistic time: This is the worst case scenario, where all the conditions are adverse or unfavorable. The maximum time which may be taken in such a situation is the pessimistic time denoted by “b”.
• Most likely time: The most realistic estimate of the time, denoted by “m” in normal conditions, is another parameter which is important in the computation of expected times and variances.

b)

Summary Introduction

To determine:The probability of completing the project in 20 months.

c)

Summary Introduction

To determine:The probability of completing the project in 23 months.

d)

Summary Introduction

To determine:The probability of completing the project in 25 months.

e)

Summary Introduction

To compute: The due date that yields a 95% chance of completion.