Lampiran 2
PENENTUAN METODE PERAMALAN TERBAIK
1. Perhitungan Metode-metode Peramalan Stasioner
1.1 Kode atau Jenis Produk = 210 mm x 30 m Kertas Profax
1000 2000
3000 4000
5000
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Periode bulan
P e
rm in
ta a
n u
n it
Gambar L2.1 Plot data permintaan yang lalu untuk item 210 mm x 30 m
Contoh Perhitungan :
a. Metode Regresi
Konstan
Tabel L2.1 Peramalan metode regresi konstan item 210 mm x 30 m
t dt
dt dt - dt
dt - dt
2
1 2464
3084,71 -620,71
385280,9 2
3200 3084,71
115,29 13291,784
3 4200
3084,71 1115,29
1243871,8 4
2800 3084,71
-284,71 81059,784
5 2400
3084,71 -684,71
468827,78 6
3604 3084,71
519,29 269662,1
7 2854
3084,71 -230,71
53227,104 8
2812 3084,71
-272,71 74370,744
9 2214
3084,71 -870,71
758135,9 10
2478 3084,71
-606,71 368097,02
11 3040
3084,71 -44,71
1998,9841 12
3364 3084,71
279,29 78002,904
13 3458
3084,71 373,29
139345,42 14
2000 3084,71
-1084,71 1176595,8
15 3364
3084,71 279,29
78002,904 16
3485 3084,71
400,29 160232,08
17 3157
3084,71 72,29
5225,8441 18
2285 3084,71
-799,71 639536,08
19 3578
3084,71 493,29
243335,02 20
3200 3084,71
115,29 13291,784
Lampiran 2
Tabel L2.1 Peramalan metode regresi konstan item 210 mm x 30 m lanjutan
t dt
dt dt - dt
dt - dt
2
21 3400
3084,71 315,29
99407,784 22
3628 3084,71
543,29 295164,02
23 3200
3084,71 115,29
13291,784 24
3848 3084,71
763,29 582611,62
TOTAL 7241867
MSE 301744,46
Perhitungan :
71 ,
3084 24
74033 24
3848 2285
... 3200
2464
1
= =
+ +
+ +
= =
∑
=
n dt
dt
n t
dt – dt’ = d
1
– d
1
’ = 2464 – 3084,71 = -620,71 dt – dt’
2
= d
1
– d
1
’
2
= -620,71
2
= 385280,9
46 ,
301744 24
7241867
1 2
= =
− =
∑
=
n d
d MSE
n t
t t
b. Metode Single Exponential Smoothing
Tabel L2.2 Peramalan metode single exponential smoothing item 210 mm x 30 m
t dt
dt dt - dt
dt - dt
2
1 2464
- -
- 2
3200 2464
736 541696
3 4200
2611,2 1588,8
2524285,4 4
2800 2928,96
-128,96 16630,682
5 2400
2903,168 -503,168
253178,04 6
3604 2802,5344
801,4656 642347,11
7 2854
2962,8275 -108,8275
11843,429 8
2812 2941,062
-129,062 16657,004
9 2214
2915,2496 -701,2496
491751,02 10
2478 2774,9997
-296,9997 88208,816
11 3040
2715,5998 324,40025 105235,52 12
3364 2780,4798
583,5202 340495,82
13 3458
2897,1838 560,81616 314514,76 14
2000 3009,3471
-1009,347 1018781,5
15 3364
2807,4777 556,52234 309717,12 16
3485 2918,7821 566,21787 320602,68
17 3157
3032,0257 124,9743
15618,575 18
2285 3057,0206
-772,0206 596015,75
19 3578
2902,6164 675,38355 456142,94 20
3200 3037,6932 162,30684 26343,511
Lampiran 2
Tabel L2.2 Peramalan metode single exponential smoothing item 210 mm x 30 m lanjutan
t dt
dt dt - dt
dt - dt
2
21 3400
3070,1545 329,84547 108798,04 22
3628 3136,1236 491,87638 241942,37
23 3200
3234,4989 -34,4989
1190,1739 24
3848 3227,5991 620,40088 384897,25
25 -
3351,6793 -
- TOTAL
8826893,6 MSE
383777,98
Perhitungan : Inisialisasi :
2 ,
= α
d
1
’ = d
1
1 1
. 1
.
− −
− +
=
t t
d d
dt α
α d
1
’ = 0,2.do + 1-0,2.do’ = - tidak ada, karena do dan do’ tidak diketahui d
2
’ = 0,2.d
1
+ 1-0,2.d
1
’ = 0,2.2464 + 0,8.2464 = 2464 d
3
’ = 0,2.d
2
+ 1-0,2.d
2
’ = 0,2.3200 + 0,8.2464 = 2611,2 dt – dt’ = d
2
– d
2
’ = 3200 – 2464 = 736 dt – dt’
2
= d
2
– d
2
’
2
= 736
2
= 541696
98 ,
383777 23
6 ,
8826893
1 2
= =
− =
∑
=
n d
d MSE
n t
t t
c. Metode Single Moving Average
