TUGAS
TEKNIK OPTIMASI
“EMPLOYEE
SCHEDULING”
Oleh
:
RISDAWATI
HUTABARAT
NPM
: 1215031064 
                          Kelas : B
JURUSAN
TEKNIK ELEKTRO
FAKULTAS
TEKNIK
UNIVERSITAS
LAMPUNG
2014
SOAL
Employed has a 24-hour-day, 7-days-a-week toll free
hotline that is being set up to answer questions regarding a new product. The
following table summarizes the number of full-time equivalent employees (FTEs)
must be on duty in a each time block.
| 
Interval | 
Time | 
FTEs | 
| 
1 | 
0-4 | 
15 | 
| 
2 | 
4-8 | 
10 | 
| 
3 | 
8-12 | 
40 | 
| 
4 | 
12-16 | 
70 | 
| 
5 | 
16-20 | 
40 | 
| 
6 | 
20-0 | 
35 | 
Constraints for Employee Scheduling
·        
Macrosoft may
hire both full-time and part time employees. The former work 8-hour shifts and
the latter work 4-hour shifts ; their respective hourly wages are $15.20 and
$12.95. Employees may start work only at the beginning of 1 of the 6 intervals.
·        
Part-time
employees can only answer 5 calls in the time a full-time employee can answer 6
calls. (i,e.,a part-time employee is only 5/6 a full-time employee.)
·        
At least
two-thirds of the employee working at any one time must be full-time employees.
Formulate an LP to determine how to
staff the hotline at minimum cost.
Solution :
Formulate an LP to determine how to
staff the hotline at minimum cost.
Decision variables:
Xt = # of full time employes that
begin the day at the start of interval t to work  
           For 8 hours
Yt = # of part time employes that
are signed interval t.
Dari tabel diatas maka diperoleh
nilai dari masing-masing interval waktu untuk memulai bekerja adalah :
X1= 0-8
X2= 4-12
X3=8-16
X4=12-20
X5=16-0
X6=20-4
Maka untuk mendapatkan nilai minimum cost adalah 
Part-time employees can only answer
5 calls in the time a full-time employee can answer 6 calls.
| 
(8
  x $ 15,2)                                     (4 x $12,95) | 
| 
Min
  $ 121,6 (X1+X2+…X6)  +    $
  51,8 (Y1+Y2+…Y6 =   | 
| 
             X1+X6                       +    
  (5/6) Y1   15 | 
| 
             X1+X2                       +     (5/6) Y2   10 | 
| 
             X2+X3                       +     (5/6) Y3   40 | 
| 
             X3+X4                       +     (5/6) Y4   70 | 
| 
             X4+X5                       +     (5/6) Y5   40 | 
| 
             X5+X6                       +     (5/6) Y6   35 | 
At least two-thirds of the employee
working at any one time must be full-time employees.
More constraints
X1+X6  (2/3)  (X6+XI+Y1)   --> 
(1/3) X1 + (1/3)X6 – (2/3)YI
 (2/3)  (X6+XI+Y1)   --> 
(1/3) X1 + (1/3)X6 – (2/3)YI   0
 0
 (2/3)  (X6+XI+Y1)   --> 
(1/3) X1 + (1/3)X6 – (2/3)YI
 (2/3)  (X6+XI+Y1)   --> 
(1/3) X1 + (1/3)X6 – (2/3)YI   0
 0
X1+X2  (2/3) 
(X1+X2+Y2)   -->
(1/3) X1 + (1/3)X2 – (2/3)Y2
  (2/3) 
(X1+X2+Y2)   -->
(1/3) X1 + (1/3)X2 – (2/3)Y2   0
 0
 (2/3) 
(X1+X2+Y2)   -->
(1/3) X1 + (1/3)X2 – (2/3)Y2
  (2/3) 
(X1+X2+Y2)   -->
(1/3) X1 + (1/3)X2 – (2/3)Y2   0
 0
X2+X3  (2/3) 
(X2+X3+Y3)   -->
(1/3) X2 + (1/3)X3 – (2/3)Y3
  (2/3) 
(X2+X3+Y3)   -->
(1/3) X2 + (1/3)X3 – (2/3)Y3  0
 0
 (2/3) 
(X2+X3+Y3)   -->
(1/3) X2 + (1/3)X3 – (2/3)Y3
  (2/3) 
(X2+X3+Y3)   -->
(1/3) X2 + (1/3)X3 – (2/3)Y3  0
 0
X3+X4  (2/3) 
(X3+X4+Y4)  -->
(1/3) X3 + (1/3)X4 – (2/3)Y4
  (2/3) 
(X3+X4+Y4)  -->
(1/3) X3 + (1/3)X4 – (2/3)Y4  0
 0
 (2/3) 
(X3+X4+Y4)  -->
(1/3) X3 + (1/3)X4 – (2/3)Y4
  (2/3) 
(X3+X4+Y4)  -->
(1/3) X3 + (1/3)X4 – (2/3)Y4  0
 0
X4+X5  (2/3) 
(X4+X5+Y5)   --> (1/3) X4 + (1/3)X5 – (2/3)Y5
  (2/3) 
(X4+X5+Y5)   --> (1/3) X4 + (1/3)X5 – (2/3)Y5  0
 0
 (2/3) 
(X4+X5+Y5)   --> (1/3) X4 + (1/3)X5 – (2/3)Y5
  (2/3) 
(X4+X5+Y5)   --> (1/3) X4 + (1/3)X5 – (2/3)Y5  0
 0
X5+X6  (2/3) 
(X5+X6+Y6)   --> (1/3) X5 + (1/3)X6 – (2/3)Y6
  (2/3) 
(X5+X6+Y6)   --> (1/3) X5 + (1/3)X6 – (2/3)Y6  0
 0
 (2/3) 
(X5+X6+Y6)   --> (1/3) X5 + (1/3)X6 – (2/3)Y6
  (2/3) 
(X5+X6+Y6)   --> (1/3) X5 + (1/3)X6 – (2/3)Y6  0
 0
Xt  0,    Yt
 0,    Yt 0      
t=1,2,3,4…..6
 0      
t=1,2,3,4…..6 
 0,    Yt
 0,    Yt 0      
t=1,2,3,4…..6
 0      
t=1,2,3,4…..6 
Hasil print screen dari ms.excel dengan
menggunakan Jensen.lib
Dari
gambar diatas maka dapat diketahui bahwa nilai value dari :
X1= 7,1                       Y1
= 0                       Dengan nilai profit= 12800,19 
X2
= 0                          Y2
= 3,5
X3=
40                         Y3 =
0
X4
=12,9                      Y4 =
20,6
X5=
27,1                      Y5 =
0
X6
=7,1                        Y6  = 0
 
 
 
 
