Operations Management assignment, If you can do these in Half hours, just send me the handshake, dont ask me question, dont offer if you know nothing about it.

The times required to complete each of eight jobs in a two-machine flow shop are shown in the table that follows. Each job must follow the same sequence, beginning with machine A and moving to machine B.

TIME (hours)

Job

Machine A

Machine B

a

16        

5        

b

3        

13        

c

9        

6        

d

8        

7        

e

2        

14        

f

12        

4        

g

18        

14        

h

20        

11        

a.

Determine a sequence that will minimize makespan time.

  The sequence is .

b.

Find machine B’s idle time.

  Idle time

 hrs  

c.

For the sequence determined in part a, how much would machine B's idle time be reduced by splitting the last two jobs in half?

  New idle time  hrs, savings of  hrs.

Given the operation times provided:

JOB TIMES (minutes)

A

B

C

D

E

F

  Center 1

20

16

43

60

35

42

  Center 2

27

30

51

12

28

24

a.

Develop a job sequence that minimizes idle time at the two work centers.

  The sequence is

 .

b.

Determine idle time of center 2, assuming no other activities are involved.

  Idle time

 minutes   

The production manager must determine the processing sequence for seven jobs through the grinding and deburring departments. The same sequence will be followed in both departments. The manager’s goal is to move the jobs through the two departments as quickly as possible. The foreman of the deburring department wants the Shortest processing time rule to be used to minimize the work-in-process inventory in his department.

PROCESSING TIME (hours)

Job

Grinding

Deburring

A

3        

6        

B

2        

4        

C

1        

5        

D

4        

3        

E

9        

4        

F

8        

7        

G

6        

2        

  a.

Prepare a schedule using Shortest processing time for the grinding department.

  The sequence is

.

b-1.

What is the flow time in the grinding department for the Shortest processing time sequence?

  Grinding flow time

   hours  

b-2.

What is the total time needed to process the seven jobs in both the grinding and deburring departments?

  Total time

 hours  

c-1.

Determine a sequence that will minimize the total time needed to process the jobs in both departments.

  The sequence is

.  

c-2.

What flow time will result for the grinding department?

  Grinding flow time

  hrs  

Given the following information on job times and due dates.

Job

Job Time (Hours)

Due Date (Hours)

a

3.5     

7      

b

2.0     

6      

c

4.5     

18      

d

5.0     

22      

e

2.5     

4      

f

6.0     

20      

a-1.

Determine the optimal processing sequence using (1) First come, first served, (2) Shortest processing time, (3) Earliest due date, and (4) Critical ratio.

  Sequence for First come, first served

  Sequence for Shortest processing time

  Sequence for Earliest due date

  Sequence for Critical ratio

a-2.

For each method, find the average job flow time and the average job tardiness. (Round your answers to 2 decimal places.)

First Come, First Served

Shortest Processing Time

  Earliest Due Date

   Critical Ratio

  Average flow time

  Average job tardiness

The Budd Gear Co. specializes in heat-treating gears for automobile companies. At 8:00 a.m., when Budd’s shop opened today, five orders (listed in order of arrival) were waiting to be processed.

Order

Order Size (units)

Per Unit Time in Heat Treatment (minutes/unit)

Due Date (min. from now)

A

16        

4            

160

B

6        

12            

200

C

10        

3            

180

D

8        

10            

190

E

4        

1            

220

a.

If the due date rule is used, what sequence should be used?

  The sequence is

.

b.

What will be the average job tardiness? (Round your answer to 2 decimal places.)

  Average job tardiness

c.

What will be the average number of jobs in the system? (Round your answer to 2 decimal places.)

  Average number of jobs

d.

Would the Shortest processing time rule produce better results in terms of average job tardiness?(Round your answer to the nearest whole number.)

   new average job tardiness is  minutes.