Assessing and Analyzing Risks

$20.$ Jordanne King, the project manager for Webjets Inter$-$

national, Inc., compiled a table showing time estimates

for each of the activities of a project to upgrade the com$-$

pany's Web page, including optimistic, most likely, and

pessimistic.

a$.$ Calculate the expected time, te$,$ foreach activity.

b$.$ Calculate the variance, o$?,$ for each activity.

Activity Optimistic $($days$)$ Most Likely $($days$)$ Pessimistic $($days$)$

$121518$

$16$

$21.$ Recently, you were assigned to manage a project to

remodel the seminar room for your company. You have

constructed anetwork diagram depicting the various

activities in the project $($Figure $7\mathrm{.}13).$ In addition, you

have asked your team to estimate the amount of time

that they would expect each ofthe activities to take.

Their responses are shown in the following table.

T MI E E S T I M A T E S $($ D A Y S $)$

$22.$ InSolved Problem $2,$ estimatethe probability that the

noncritical path B$-$F$-$G will take more than $20$ weeks.

Hint: Subtract from $1\mathrm{.}0$ the probability that B$-$F$-$G will

take $20$ weeks or less.

$23.$

The directorof continuing education at Bluebird Uni$-$

versity just approved the planningfor a sales training

seminar. Her administrative assistant identified the vari$-$

ous activities that must be done and theirrelationships

to each other, asshown in fable $7\mathrm{.}13.$

Start

Finish

Activity

Optimistic

Most Likely

Pessimistic

$1$

$11$

A FIGURE $7\mathrm{.}13$

Network Diagram for Problem $21$

a$.$ What is the expected completion time of the project?

b$.$ What is the probability ofcompletingthe project in

$21$ days?

c$.$ What is the probability of completing the project in

$17$ days?