I need assistance with the following questions in: Project Scheduling.
This is a follow up to a question answered earlier. Question 1) was answered.
1) A company decides to plan a project, with activities, precedences and deterministic durations given in the following table:
Activity i |
Duration (days) |
Immediate Predecessors |
A |
32 |
none |
B |
21 |
none |
C |
30 |
none |
D |
45 |
A |
E |
26 |
A, B |
F |
28 |
C |
G |
20 |
E, F |
2) The company decided that the project in the previous problem has to be expedited in order to optimize (minimize) the project cost. Expediting can be used to trade direct cost for indirect cost, since expediting the project reduces the indirect cost of the project by a fixed amount per day, while expediting an activity increases its total direct cost. The Accounting Department found that indirect costs amount to $100 per day, while activity direct costs as well as their normal and expedited times are given in the table below.
Activity |
Normal Time (days) |
Expedited Time (days) |
Normal Cost ($) |
Expedited Cost ($) |
A |
32 |
26 |
200 |
500 |
B |
21 |
20 |
300 |
375 |
C |
30 |
30 |
200 |
200 |
D |
45 |
40 |
200 |
800 |
E |
26 |
20 |
700 |
1,360 |
F |
28 |
24 |
1,000 |
1,160 |
G |
20 |
18 |
400 |
550 |
From this table you can compute the direct cost incurred by expediting an activity by one day.
Questions:
1) What is the optimal time to complete the project?
2) What is the optimal project cost?
Given the activity sequence and timings the following are the paths (in AOA notation):
A-D (length 77)
A-E-G (length 78, critical path)
B-E-G (length 67)
C-F-G (length 78, critical path)
Next we find the details on the crash cost for the activities in the critical path(s).
Taking critical path A-E-G we show the details in the corresponding table.
Similarly for critical path C-F-G we show in the corresponding table.
Since path G is common for both we can either crash it by 1 day costing $75. However instead of this we could choose to crash the lowest cost activities in both the critical paths (such as A and F) but the total cost would be 50 + 40 = $90 which is more than $75. So we crash G by 1 day as we save indirect cost of $100. Now we have 3 paths of the same length 77 (all become critical)
A-D (length 77 as earlier, now critical path)
A-E-G (length 77 after crashing, still critical path)
B-E-G (length 66 now)
C-F-G (length 77 after crashing, still critical path)
Now we construct the activity table for the newly critical path A-D we get the table as shown.
Now choosing the lowest crash cost activity A we can crash it reducing the critical paths of A-D and A-E-G by 1 day and costing $50. But in order to reduce the length of the 3rd critical path C-F-G by 1 day we choose activity F costing $40. So all the three critical paths are reduced by 1 day costing in total $(40+50) = $90 per day. Since this is less than the total indirect cost savings of ...
Q: What are the four ways of increasing self-efficacy as proposed by Albert Bandura? How can you apply ...
A: Self-efficacy:It is the ability of an individual in one's belief to succeed in the accomplishment of...
Q: I need a detailed assistance to solve this problem in: Operations Analysis. #4) A greengrocer has ex...
A: Compute the space consumed by Lettuce:
Q: Describe post-sale service arrangements the firm does or should provide?Explain how the firm’s repai...
A: Click to see the answer
Q: The Reliance Manufacturing Company produces an aircraft part. The company can produce the part entir...
A: Information provided:The following information is necessary in order to determine the total daily ou...
Q: Choose two different student organizations in your school.List the group characteristics of each of ...
A: Let the two groups be student activities center and the canteen food committee:Student activities ce...
Q: What are some guidelines for time management?
A: Basic definition of "Time management is the process of planning and organizing how to manage your ti...
Q: you are asked to develop an experiment for a study of the effect that has on the response rates sec...
A: Here some variables during a setting and observe however it affects the topics being studied.In this...
Q: The Sanders Garden Shop mixes two types of grass seed into a blend. Each type of grass has been rate...
A: Introduction:The given problem is a linear programming Cost Minimization problem. The problem is sol...
Q: The equation y = 210 + 3x is used to predict quarterly demand where x = 0 in the second quarter of l...
A: Calculating the forecast for the third quarter of the year. We have,Y = 210 + 3xHere,x = Third quart...