Please let me know if I figured out correctly which process to crash by 1 minute
ID: 361850 • Letter: P
Question
Please let me know if I figured out correctly which process to crash by 1 minute. The diagram is in minutes. Cost information is in the chart below.
2 Critical paths - PG1, PG2, FA2, FA3, FA4 and WH1, WH2, WH3, FA3, FA4
I chose to crash a common process between the 2 paths, FA4 with a cost of .53. My new cost will be $30.93
Is this correct?
And to crash by 1 day, I needed to shorten the time by 9 minutes. I chose to crash PG2 by 4 minutes at a cost of .28 and WH2 by 4 minutes at a cost of .24 and FA4 by 1 minute at a cost of .53. My new cost is $31.45.
Is this correct?
MR01 SP32 PG-1 FR-1 WH-1 13 FF-1 15 FR-2 FF-3 PG-2 15 18 FR-3 FF-4 16 17 38 BR07 24 38 FA-2 13 FA-1 25 38 38 LS LF ES LS FA-3 FA-4 and 1b. The critical paths are PG-1... PG-2 FA-2 WH-1... WH-2... WH-3... FA-3... FA-4. FA FA-2 FA-3 FA-4 25 23 38 38 38 1c. Under normal conditions it will take 48.33 hours to complete 50 bicycles from start to finish. 58 minutes * 50 bicycles-2900/60= 48.33 hours 58 58 FF-2 FF-3 FF-4 FR-1 FR-2 FR-3 1d. The cost to make 50 bicycles is $1,520 in labor costs. $30.40 cost of labor for 1 bicycde 50 $1,520 le. To make 15% profit on each bicycle, we need to charge the customer $34.92 in labor costs. 30.40*.15 $4.56 $30.40+$4.56-$34.92 PG-2 25 10 25 24 38 WH-3 24Explanation / Answer
4.
Summary of Critical activities and crashing cost per minute
Critical Path 1
Critical Path 2
Activities
Cost per minute
crash periods available
Activities
Cost per minute
crash periods available
PG-1
0.34
3
WH-1
0.09
2
PG-2
0.07
4
WH-2
0.06
1
FA-2
0.08
4
WH-3
0.09
4
FA-3
1.2
11
FA-3
1.2
11
FA-4
0.53
5
FA-4
0.53
5
If FA-4 is crashed by 1 minute, the total crashing cost is $0.53.
Instead consider Activity PG-2 (0.07) of path 1 and activity WH-2 (0.06) of Path 2. Both activities have lowest crash cost per minute along respective critical paths. If both activities are crashed by 1 minute, the total project completion time will reduce by 1 minute. The total cost of crashing project by 1 minute = 0.07 + 0.06 = $0.13 which less than $0.53.
It is less costly to crash critical two activities simultaneously instead of crashing common activity.
New project completion time = 57 minutes
Thus, crash the activities PG-2 and WH-2 by one day each. The new cost per bicycle will be $30.40 + $0.13 = $30.53
If further project duration has to be crashed by 1 minute then consider PG-2 and WH-3 for crashing.
Critical Path 1
Critical Path 2
Activities
Cost per minute
crash periods available
Activities
Cost per minute
crash periods available
PG-1
0.34
3
WH-1
0.09
2
PG-2
0.07
4
WH-2
0.06
1
FA-2
0.08
4
WH-3
0.09
4
FA-3
1.2
11
FA-3
1.2
11
FA-4
0.53
5
FA-4
0.53
5