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Monday, December 26, 2011

A question on Project Management

Given below is a WBS of a project.

 

              

Activity

Activity time in days

Immediate Predecessors

a

30

--

b

20

--

c

15

a

d

18

b

e

32

b

f

25

c, d

g

22

c, d

h

17

e, g

i

8

e

j

15

i

 

 Draw an activity network diagram for this project and find the critical path by finding earliest time and latest time of various events. What is the project completion time?

A question on forecasting (time series)

The recorded number of claims in motor insurance in last 7 months are as follows:
 
35, 70, 45, 20, 50, 80 and 60.
 
Use moving average method to forecast the number of claims for next 3 months based on past 4 months data. The actual numbers of claims in 8th and 9th months are 100 and 30 respectively. 
 
Take a smoothing factor of 0.3 to forecast the 10th month data using exponential smoothing forecasting technique. Don’t change the forecast of previous months.

Simulation Problem

A health insurance product is designed targeting persons working in Education sector. The age profile of people who has taken this policy is as follows:

 

21- 35 years     25%

35+ - 45 years 30%

45+ - 55 years 25%

55+  years       20%

 

Probability of claim is 0.2 in all the age groups however the claim amount varies linearly between Rs. 15000 to Rs. 80000 for age up to 45 years and between Rs. 30000 to Rs. 200000 for age above 45 years. Do a simulation run of length 10 to understand the claim pattern.

 

Use following random numbers 5971, 9987, 1741, 7431, 188, 5333, 3680, 4883, 5036, 5407, 2763, 7194, 3395, 3632, 1109, 9943, 6690, 6408

Tuesday, November 8, 2011

Class test questions on Simplex method 8th Nov 2011

 

1.                  Below Simplex Table is not a basic feasible solution table.  Why?

Convert that to a basic feasible solution table.

 

 

 

p

x1

x2

x3

s1

s2

s3

R.H.S.

P

1

0

0

-10

80

30

0

15000

x2

0

0

3

27

45

18

0

183

x1

0

1

0

12

73

24

0

115

s3

0

0

0

-15

27

-12

-1

-40

 

 

2.                  Below Simplex Table is an optimal table.  Why?

It also has alternate optimal.  Find that. (No need to prepare the complete table.)

 

Since it has an alternate optimal, it has infinite number of optimal solution.  Can you provide some expression to find as many optimum solutions as you want in this case? (send this by mail to get upto 10 marks from the class involvement part.  Deadline: 9/11/11, 5 PM)

 

 

 

p

x1

x2

x3

s1

s2

s3

R.H.S.

P

1

25

0

0

10

0

0

7500

x3

0

-15

10

1

8

0

0

305

s2

0

12

25

0

-5

1

0

670

s3

0

3

15

0

12

0

1

320

 

 

 

Saturday, November 5, 2011

Sensitivity analysis in Linear programming

This tutorial will be helpful in understanding sensitivity analysis. This seems to be very close to the way we were discussing in the class. Also see other pages on the site.
 
 

Friday, October 21, 2011

Linear Programming Resource

Contents available at below site nicely explain Linear Programming, graphical method and Simplex method. You may also like to navigate through other pages of the site.
 

Tuesday, October 18, 2011

Linear Programming- Graphical Method- Test question

A Carpenter manufactures tables and chairs. He has all the resources in abundance except wood and nails. The profitability and resource requirements for the two products are given in following table. The availability of resources per day is also given. How many tables and chairs he should manufacture daily so that his profit is maximized? Formulate the linear programme and solve that using graphical method.

 

 

Table

Chair

 

Profit/unit->

20$

30$

Availability/day v

 

 

 

 

Wood/unit in kg.

40

30

1200

Nails/unit in number

25

40

1000

 

If the profit/unit on table increases and rest of the data remains same, find the increased value of profit/unit on table so that the optimum product mix doesn’t change.

Tuesday, October 11, 2011

Evaluation of QT2 (2011-13)

Unannounced Class tests: 20 marks. Best 2 out of 4 tests of 10 marks each.

 

Announced Class test: 10 marks. One test of 10 marks.

 

Class Performance: 20 marks. Your roll number will be noted during the class if you ask good question. Depending on the number of good questions asked by you in the class, your marks in this part will be decided as per below table.

 

Number of times your roll number is noted

Marks

7 or more

19 or 20

6

17 or 18

5

15 or 16

4

13 or 14

3

11 or 12

Less than 3

Come for viva

 

Your response to questions asked in the class will be considered in awarding one of the two marks as per the above table.

 

Group work/ Presentation: 20 marks

 

End term examination: 30 marks.

Project Management - An Exercise

There is a race ground with 15 racetracks. A team has to complete all the 15 tracks to complete the race. There are few tracks that can be done in the beginning. However for other tracks it is necessary to finish some other tracks and press the finish button then only the entrance gate opens. You can form your team of as many members as you want to finish the race in best possible time. The time required to complete a track and the tracks that needs to be completed before starting this track are given in the below table.

 

 

Track

Time required in minutes

Tracks to be completed before starting this track

A

45

None

B

25

None

C

15

None

D

20

A

E

30

B

F

30

C

G

15

D

H

40

E, F

I

40

C

J

35

G, H

K

10

H

L

15

I

M

35

I

N

20

K, L

O

30

M

 

Time required in changing the track or any other related activities are already included in the time given above. So, there is no need to consider any other time element.

 

  1. Find the minimum time in which the race can be completed and for that what should be your team size. A team member can cover more than one track one after other.

 

  1. Just before the start of the race, your team members inform you that they will be late by about 4 minutes. You can run any of the A, B, or C tracks. Which one you will run? Will it impact your team overall performance in the race?

 

  1. You are given two cycles that can be used on any two tracks in the race. Use of cycle on a track reduces the time requirement for that track by 40%. In which two tracks would you use them to get the best race time?

 

  1. Let there be another track P introduced in the race that needs to be completed before N can be started. However to start P it is necessary to finish track C. Time required to complete the track P is 50 minutes. What would be the impact of introduction of this track on your race completion time with and without cycle?