Expected task time

Task variance

Project variance

$($variances of activities on critical path$)$

ES $=$ Earliest Start $=$ Max $($EF of all immediate predecessors$)$

EF $=$ Earliest Finish $=$ ES $+$ Activity time

LF$=$ Latest Finish $=$ Min $($LS of all immediate successors$)$

LS $=$ Latest Start $=$ LF $$ Activity time

Slack $=$ LS $$ ES or Slack $=$ LF $$ EF

Using Table $1,$ type in the correct whole number for each task$$s

expected task time $($te$)$

earliest start time $($ES$)$

earliest finish time $($EF$)$

latest start time $($LS$)$

latest finish time $($LF$),$ and

slack.

Type Yes or No in the space provided to indicate whether the task is a critical task.

In the last column, enter the correct number for task variance to two decimal places $($for example, if the number is $0\mathrm{.}66666667$ then enter $0\mathrm{.}67$; if the number is $0,$ enter $0\mathrm{.}00).$

In the last row, enter the correct whole number for the expected project completion time.

In the last row, enter the correct number using two decimal places for the project variance.

Note that the last $8$ columns of Table $1$ have blank cells for you to fill in with each task$$s te$,$ ES$,$ EF$,$ LS$,$ LF$,$ slack, critical status, and variance while the last row has $2$ cells for you to fill in expected project time and project variance.

NOTE: If you are unable to select any of the cells toward the right$-$hand side of the PERT Table, please click on a cell within the same row on the left$-$hand side of the table and use the 'Tab' key to tab over to the cell you would like to edit.

Table $1$ PERT Problem Project Tasks: Times Are in Hours.

Note: Immed Predec$=$immediate predecessors, a$=$optimistic, m$=$most likely, b$=$pessimistic, te$=$expected task, ES$=$earliest start, EF$=$earliest finish, LS$=$latest start, LF$=$latest finish task times.

Task

Immed Predec

a m b

te

ES

EF

LS

LF

Slack

Critical

Task Variance

$($whole #$)($whole #$)($whole #$)($whole #$)($whole #$)($whole #$)($Yes$/$No$)(2$ decimal places$)$

A

$--$

$567$

B

$--3615$

C

$--369$

D

A$,$ B $555$

E

C $234$

F

D$,$ E $3411$

Expected Project Completion time $($whole #$)$

Project Variance $(2$ decimal places$)$