Charlie Cook was able to determine the activity times for constructing his chemical contaminant tracking machine. Cook would like to determine$$ ES$,$ EF$,$ LS$,$ LF$,$ and slack for each activity. The total project completion time and the critical path should also be determined. Here are the activity$$ times:

$$

Activity

Time$($weeks$)$

Immediate$$ Predecessor$($s$)$

Activity

Time$($weeks$)$

Immediate$$ Predecessor$($s$)$

A

$7$

minus

E

$3$

B

B

$6$

minus

F

$7$

B

C

$3$

A

G

$10$

$$C$,$ E

D

$2$

A

H

$8$

$$D$,$ F

Part $2$

$$Charlie$\text{'}$s earliest start$($ES$)$ and earliest finish$($EF$)$ are:

Part $3$Part $4$Part $5$Part $6$Part $7$Part $8$Part $9$

Activity

ES

EF

A

$$

$0$

$7$

B

$0$

$$

$6$

C

$$

$7$

$10$

D

$7$

$$

$9$

E

$$

$6$

$9$

F

$6$

$$

$13$

G

$$

$10$

$20$

H

$$

$13$

$21$

Part $10$

$$Charlie$\text{'}$s latest start$($LS$)$ and latest finish$($LF$)$ are:

Part $11$Part $12$Part $13$Part $14$Part $15$Part $16$Part $17$

Activity

LS

LF

H

$13$

$$

$21$

G

$11$

$$

$21$

F

$6$

$$

$13$

E

$8$

$$

$11$

D

$11$

$$

$13$

C

$8$

$$

$11$

B

$0$

$$

$6$

A

$1$

$$

$8$

Part $18$

The slack times$$ are:

Part $19$Part $20$Part $21$Part $22$Part $23$Part $24$Part $25$

Activity

Slack

A

$$

$1$

B

$$

$0$

C

$$

$1$

D

$$

$4$

E

$$

$2$

F

$$

$0$

G

$$

$1$

H

$$

$0$

Part $26$

The activities on the critical path are

B $-$ F $-$ H

$.$

Part $27$

The total project completion time for Charlie$=$

$$

$21$ weeks.