Monday, September 17, 2012

sequencing numericals


Q1. At valley hospital nurses beginning a new shift report to a central area to receive their primary assignments. not every nurses is as efficient as another with particular kinds of patients. Given the following patient roster          care levels, and time estimates, assign nurses to patients to optimize efficiency. Also, determine how long it will take for nurses to complete their routine tasks on the shift.

atpatient
Care level
Nurse1
Nurse2
Nurse3
Nurse4
Jones
A2
3
5
4
3
hathaway
B2
2
1
3
2
bryant
B1
3
4
2
2
sweeney
A1
4
3
3
4

ANS


Nurse1
Nurse2
Nurse3
Nurse4
A2
0
2
1
0
B2
1
0
2
1
B1
1
2
0
0
A1
1
0
0
1

B2
N2
A1
N3
B1
N4
A2
N1
Time take
N1    take    3
N2    take   1
N3    take    3
N4    take     2

Q2. Valley hospital wants to focus on customer perceptions of quality , so it has asked its patients to evaluate the nursing staff and indicate preference for assignment. Reassign the nursing staff to obtain the highest customer approval rating possible .

Patient
Nurse1
Nurse2
Nurse3
Nurse4
A Jones
89
95
83
84
B Hathaway
88
80
96
85
C Bryant
87
92
82
84
D Sweeney
93
82
86
94

ANS


N1
N2
N3
N4
A
6
1
13
12
B
8
16
0
11
C
9
4
14
12
D
3
14
10
2


N1
N2
N3
N4
A
5
0
12
11
B
8
16
0
11
C
5
0
10
8
D
1
12
8
0


N1
N2
N3
N4
A
4
0
12
11
B
7
16
0
11
C
4
0
10
8
D
0
12
8
0

N1= A
N2=C
N3=B
N4=D
Q.no 3-
Ans -
Item
1
2
3
4
5
Chocolate Mint
30
18
26
17
15
Peanut Butter
23
22
32
25
30
Short Bread
17
31
24
22
29
Fudge Delight
28
19
13
18
23
Macarooons
23
14
16
20
27




Matrix :
30
18
26
17
15
23
22
32
25
30
17
31
24
22
29
28
19
12
18
23
23
14
16
20
27

15
3
11
2
0
1
0
10
3
8
0
14
7
5
12
15
6
0
5
10
9
0
2
6
13

Crosses line not equal to order of matrix so,
15
3
11
0
0
1
0
10
1
8
0
14
7
3
12
15
6
0
3
10
9
0
2
4
13

                                                
15
3
11
0
0
0
0
10
0
7
0
15
7
3
12
15
7
0
3
10
9
0
2
4
13


Item

Chocolate Mint
5
Peanut Butter
4
Short Bread
1
Fudge Delight
3
Macarooons
2


Q. no -4
Answer –
Product
A
B
C
D
E
1
17
10
15
16
20
2
12
9
16
9
14
3
11
16
14
15
12
4
14
10
10
18
17
5
13
12
9
15
11

Matrix :
3
10
5
4
0
8
11
4
11
6
9
4
6
5
8
6
10
10
2
3
7
8
11
5
9

3
10
5
4
0
4
7
0
7
2
5
0
2
1
4
4
8
8
0
1
2
3
6
0
4

A
B
C
D
E
1
10
5
4
0
2
7
0
7
2
3
0
2
1
4
2
8
8
0
1
0
3
6
0
4

E
1
C
2
B
3
D
4
A
5



Capture.PNG
7.
Answer


Questn 9
s.p.t.
typing
proofing
1
-30
20
2
90
25
3
60
15
4
-45
30
5
75
60
6
-20
30

Sol.
Chap
Typing
Proofing

6
20
30
20
1
30
20
50
4
45
30
95
6
60
15
155
5
75
60
230
2
90
25
320

Total completion time=320 days
Avg. Flow time=(20+50+95+155+230+320)/6
=145 days.
Avg. No. Of jobs each in same  days=1.22days
Avg. Job lateness=(0+20+50+95+155+230)/6
=91.6 days
10.



1
8
5
2
15
10
3
6
5
4
5
10
5
17
15
6
10
10
7
5
3
8
4
15
9
12
10
10
20
3







8
4
4
15
4
5
9
10
7
5
14
3
3
6
20
5
1
8
28
5
6
10
38
10
9
12
50
10
2
15
65
10
5
17
52
15
10
20
92
3


time completion=92 days
avg. Flow time=40.2
avg. No. Of jobs in same day=41.2
avg. Job lateness=32.1

Question 11-jobs processed through Percy machine shop pass through three operation milling, grinding and turning. the hours required for each of these operation is as follow:-
Sequence the operation and make the Gantt chart:-
Jobs
Milling
Grinding
Turning
 A
5
1
4
 B
2
2
5
 C
3
2
1
 D
0
3
0
 E
4
1
2

Q 12- Given that all the jobs listed below must be machined first, then polished, determine a sequence that will minimize the time required to process all 6 jobs. Chart the schedule on a gantt chart and indicate the makespan.
Jobs
MACHINING
        POLISHING



 A
5.0
4.0



 B
7.0
3.0



C
3.0
2.0



D
2.0
1.0



E
2.0
3.0



        F                                     6.0                          5.0
Ans-  Idle time for M1= 1 min
          Idle time for M2= 4 min




ASSIGNMENT QUESTIONS

Q13  .Given the prep. And painting time in days for following  five houses.Chart out your sequence on gantt charts and calculate the makespan.
Houses                                    
Prep.
Paint
Addison
4
2
Brown
3
6
Clayton
6
4
Daniels
5
6
Ebersole
1
4

ANS—
scan0028.jpg
Q14. Sequence the houses in previous problem by SPT and SLACK.How much time is saved with johnsons rule ?
ANS--                                     SLACK

scan0027.jpg
Time saved= 27-23=4
SPT
scan0028.jpg
Time saved=25-23=2
Q.15 Job A,B,C, & D must be processed through the same machine centre .Sequence  the following Jobs by
a.SPT
b. SLACK
JOB
PROCESSING TIME
DUE DATE
A
20
20
B
10
15
C
30
50
D
15
30

Calculate the mean flow time ,mean tardiness and max tardiness .which sequencing rule would you recommend? Why?
Ans:
According to
SPT
JOB
PROCESSING TIME
DUE DATE
FLOW TIME
B
10
15
1 0
D
15
30
25
A
20
20
45
C
30
50
75

According to slack rule
JOB
PROCESSING TIME
DUE DATE
FLOW TIME
SLACK
A
20
20
45
0
B
10
15
1 0
5
D
15
30
25
15
C
30
50
75
20



RULE
TOTAL COMPLETION TIME
AVG. TIME FLOW
AVG. NO. OF JOBS
AVG. JOB LATENESS
AVG. JOB EARLINESS
NO. OF TARDI JOBS
SPT
75
38.7
2.066
12.5
2.5
3
SLACK
75
38.7
2.23
13.75
0
3

Mean tardiness = 0.75
Maximum tardiness = 3

Shortest Path time sequencing is preferred because in this case avg. Job lateness is less and avg. Job earliness is more.

Q.16 Sequence the following jobs by (a)SPT (b)DDATE, and (c)SLACK .Calculate the mean flow time    mean tardiness and max tardiness .which sequencing rule would you recommend? Why?
JOB
PROCESSING TIME
DUE DATE
A
5
8
B
3
5
C
9
18
D
6
7

Sol.
SPT:
JOB
PROCESSING TIME
DUE DATE
FLOW TIME
B
3
5
3
A
5
8
8
D
6
7
14
C
9
9
23

Avg. Flow time = (3+8+14+23)/4 = 8.75
No. of tardi jobs = 2

SLACK:
JOB
PROCESSING TIME
DUE DATE
FLOW TIME
C
9
9
9
D
6
7
15
B
3
5
18
A
5
8
23

Avg. Flow time = (9+15+18+23)/4 = 16.25
No. of tardi jobs = 3

DUE DATE:
JOB
PROCESSING TIME
DUE DATE
FLOW TIME
B
3
5
3
D
6
7
9
A
5
8
14
C
9
18
23

Avg. Flow time = (3+9+14+23)/4 = 12.25
No. of tardi jobs = 2



JOB
AVG. FLOW TIME
NO. OF TARDI JOBS
MAX. TARDINESS
SPT
8.75
2
14
SLACK
16.25
3
15
DUE DATE
12.25
3
6



17  Complete the report

period
1
2
3
4
5
total
Planned input
50
55
60
65
65
295
Actual input
50
50
55
60
65
280
Deviation
0
-5
-5
-5
0
-15
Planned output
65
65
65
65
65
325
Actual output
60
60
60
60
60
300
Deviation
-5
-5
-5
-5
-5
-15
Backlog 30
20
10
5
5
10












18 complete the table

Period
1
2
3
4
5
total
Planned input
50
55
60
65
65
295
Actual input
40
50
55
60
65
270
Deviation
-10
-5
-5
-5
0
-25
Planned output
50
55
60
65
65
295
Actual output
50
50
55
60
65
280
Deviation
0
-5
-5
-5
0
-15
Backlog 10
0
0
0
0
0


Q: 19
Kim jonshan R.N. the charge nurse of the antepartum ward of city hospital , need help in scheduling the nurse workforce for next work.

(1) Create the employee schedule that will meet the demand requirements &garuntee each nurse  2 days off per week.
ANS:
Day of week
Mo
Tu
We
Th
Fr
St
su
No of nurse
3
3
4
5
4
3
3
Kim jonshan
O
X
X
X
X
O
x
Tom swan
O
X
X
X
X
O
x
Flo cology
X
O
X
X
X
X
o
Shelli
X
O
X
X
X
X
o

Troung
X
X
O
X
O
X
x

(2) Revise the schedule so that 2 days off are consecutive.
ANS:
Day of week
Mo
Tu
We
Th
Fr
St
su
No of nurse
3
3
4
5
4
3
3
Kim jonshan
o
o
x
x
x
x
x
Tom swan
O
O
x
X
X
X
X
Flo cology
X
X
O
X
O
X
X
Shelli
X
X
X
X
X
O
o

Troung
x
x
X
x
x
o
o

Here  o = off days
        X= working day
Flo cology not have consecutive off days .

Q 20:
Rosemary needs help in scheduling volunteers . create a work schedule that will meet the requirements ,given that a volunteer will only work 4 days per week .try to make the work consecutive.
Days of weeks
Mo
Tu
We
Th
Fr
St
Su
No. of volunteers
4
3
2
3
6
4
2
Rosemary







Albert







Richard







Gail







Shelly







Karen








ANS:
Days of weeks
Mo
Tu
We
Th
Fr
St
Su
No. of volunteers
4
3
2
3
6
4
2
Rosemary
O
O
O
X
X
X
X
Albert
O
O
O
X
X
X
X
Richard
X
O
O
X
X
X
O
Gail
X
X
O
O
X
X
O
Shelly
X
X
X
O
X
O
O
Karen
X
x
x
O
x
O
O

3 Consecutive offdays possible for  only 2 volenteer &for remaining  2 consecutive off days .


Q21
Job
1
2
3
4
5
6
M/C  1
25
30
60
20
35
45
M/C 2
25
15
40
25
30
70

Find idle time, flow time and total time using gantt chart.
Ans  1
Sequence--  4 6 3 5 1 2
scan0026.jpg
Idle time – machine 1 –30
                 Machine 2 – 40
Total time -- 245

Q22
Job
M1
M2
M3
M4
A
7
11
2
14
B
18
15
18
13
C
4
11
14
18
D
14
27
32
21
E
6
16
14
16

Ans 2
M1-M4
scan0028.jpg

M1+M2--M3+M4
scan0027.jpg

M1+M2+M3—M2+M3+M4

scan0027.jpg





Q.no 10-
What the function are typically performed by a production control department ?

Ans –
Production control department responsibilities consist of
1. Loading—checking the availability of material, machines, and labour. The MRP system
plans for material availability. CRP converts the material plan into machine and
labour requirements, and projects resource overloads and under loads. Production
control assigns work to individual workers or machines, and then attempts to
smooth out the load to make the MRP schedule "doable." Smoothing the load is
called load levelling.
2. Sequencing—releasing work orders to the shop and issuing dispatch lists for individual
machines. MRP recommends when orders should be released (hence the name,
planned order releases). After verifying their feasibility, production control actually
Releases the orders. When several orders are released to one machine center, they must
be prioritized so that the worker will know which ones to do first. The dispatch list
contains the sequence in which jobs should be processed. This sequence is often based
on certain sequencing rules.
3. Monitoring—maintaining progress reports on each job until it is completed. This is
important because items may need to be rescheduled as changes occur in the system.
In addition to timely data collection, it involves the use of Gantt charts and input/output
control charts.
Q.no 11 –
Explain Johnsons rule and its Procedure .
Ans-Since few factories consist of just one process, we might wonder if techniques exist that will
produce an optimal sequence for any number of jobs processed through more than one
machine or process. Johnson's rule finds the fastest way to process a series of jobs through a
two-step system in which every job follows the same sequence through two processes. Based
on a variation of the SPT rule, it requires that the sequence be "mapped out" to determine
the final completion time, or makespan, for the set of jobs. The procedure is as follows:
1. List the time required to complete each job at each process. Set up a one-dimensional
matrix to represent the desired sequence with the number of slots equal to the number
of jobs.
2. Select the smallest processing time at either process. If that time occurs at process 1,
put the associated job as near to the beginning of the sequence as possible.
3. If the smallest time occurs at process 2, put the associated job as near to the end of the
sequence as possible.
4. Remove the job from the list.
5. Repeat steps 2-4 until all slots in the matrix have been filled or all jobs have been
sequenced.
Q.no 3-
Ans -
Item
1
2
3
4
5
Chocolate Mint
30
18
26
17
15
Peanut Butter
23
22
32
25
30
Short Bread
17
31
24
22
29
Fudge Delight
28
19
13
18
23
Macarooons
23
14
16
20
27




Matrix :
30
18
26
17
15
23
22
32
25
30
17
31
24
22
29
28
19
12
18
23
23
14
16
20
27

15
3
11
2
0
1
0
10
3
8
0
14
7
5
12
15
6
0
5
10
9
0
2
6
13

Crosses line not equal to order of matrix so,
15
3
11
0
0
1
0
10
1
8
0
14
7
3
12
15
6
0
3
10
9
0
2
4
13

                                                
15
3
11
0
0
0
0
10
0
7
0
15
7
3
12
15
7
0
3
10
9
0
2
4
13


Item

Chocolate Mint
5
Peanut Butter
4
Short Bread
1
Fudge Delight
3
Macarooons
2


Q. no -4
Answer –
Product
A
B
C
D
E
1
17
10
15
16
20
2
12
9
16
9
14
3
11
16
14
15
12
4
14
10
10
18
17
5
13
12
9
15
11

Matrix :
3
10
5
4
0
8
11
4
11
6
9
4
6
5
8
6
10
10
2
3
7
8
11
5
9

3
10
5
4
0
4
7
0
7
2
5
0
2
1
4
4
8
8
0
1
2
3
6
0
4

A
B
C
D
E
1
10
5
4
0
2
7
0
7
2
3
0
2
1
4
2
8
8
0
1
0
3
6
0
4

E
1
C
2
B
3
D
4
A
5

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