Question

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Problem 9-24 (Algorithmic)

Office Automation, Inc., developed a proposal for introducing a new computerized office system that will standardize the electronic archiving of invoices for a particular company. Contained in the proposal is a list of activities that must be accomplished to complete the new office system project. Use the following relevant information about the activities:

		Immediate		Time (weeks)			Cost ($1000s)
Activity	Description	Predecessor(s)		Normal	Crash		Normal	Crash
A	Plan needs	—		9	8		30	50
B	Order equipment	A		8	6		120	150
C	Install equipment	B		10	7		100	160
D	Set up training lab	A		7	6		40	50
E	Conduct training course	D		10	8		50	75
F	Test system	C, E		3	3		60	—

1. Which project network is correct?

   (i)		(ii)
   (iii)		(iv)

2. Develop an activity schedule. If your answer is zero, enter “0”.

   Earliest

   Latest

   Earliest

   Latest

   Critical

   Activity

   Start

   Start

   Finish

   Finish

   Slack

   Activity (Yes or No)

   A

   B

   C

   D

   E

   F

3. What are the critical activities, and what is the expected project completion time?
   
   Critical Path:  
   
   Expected project completion time = _____ weeks.
4. Assume that the company wants to complete the project in six months or 26 weeks. What crashing decisions do you recommend to meet the desired completion time at the least possible cost? Work through the network and attempt to make the crashing decisions by inspection.

   Crash Activities	Number of Weeks	Cost ($1000s)
   A	1
   B	2
   C	1
   D	1
   E	1

5. Develop an activity schedule for the crashed project. If your answer is zero, enter “0”.

   Earliest

   Latest

   Earliest

   Latest

   Critical

   Activity

   Start

   Start

   Finish

   Finish

   Slack

   Activity (yes or no)

   A

   B

   C

   D

   E

   F

6. What added project cost is required to meet the six-month completion time?
   
   Total added cost due to crashing $  _______.

Answer 1

Project Schedule

Activity EST LST EFT LFT Slack Critical Activity(Yes/No)

A 0 0 9 9 0 Yes

B 9 9 17 17 0 Yes

C 17 17 27 27 0 Yes

D 9 10 16 17 1 No

E 27 27 30 30 0 Yes

Critical Path is A-B-C-F

Total Project Completion Time is = 9+8+10+3=30 weeks

Cost Slope is:-

A (50-30/)/1 = 20 per day

B (150-120)/2= 15 per day

C (160-100)/3 =20 per day

D (50-40)/1 = 10 per day

E (75-50)/2 =12.5 per day

F -

Crashing Activity

1. First crash common activity A by 1 day

2. Then crash common activity F by 2 days

3. then crash B by 1 day.

Project Schedule(Revised)

Activity EST LST EFT LFT Slack Critical Activity(Yes/No)

A 0 0 8 8 0 Yes

B 8 8 15 15 0 Yes

C 15 15 25 25 0 Yes

D 8 8 15 15 0 Yes   

E 15 15 25 25 0 Yes

F 25 25 26 26 0 Yes

Revised Schedule=26 days

Total added cost of project= Crashing 1+2+3

= $ 20+$25+$15

= $60