PERAMALAN PRODUK IRAWAN 683 – PT. JWL
Irawan 682 Bulan
Demand
Januari 101.850
Februari 110.329
Maret 119.021
April 143.705
Mei 115.259
Juni 124.025
Juli 115.372
Agustus 142.395
September 191.647
Oktober 122.280
November 105.624
Desember 145.989
Total 1.537.494
Metode Peramalan Terpilih: •
Metode Eksponensial •
Metode Kuadratis
1. Metode Eksponensial
EKSPONENSIAL t
y lny
t.lny t²
y 1
101.850 11,53
11,53 1
112.965
2 110.329
11,61 23,22
4
115.263
3 119.021
11,69 35,06
9
117.607
4
143.705 11,88
47,50 16
119.999
5 115.259
11,65 58,27
25
122.439
6 124.025
11,73 70,37
36
124.930
7 115.372
11,66 81,59
49
127.471
8
142.395 11,87
94,93 64
130.063
9 191.647
12,16 109,47
81
132.709
10 122.280
11,71 117,14 100
135.408
11 105.624
11,57 127,24 121
138.162
12
145.989 11,89
142,70 144
140.972
78 1.537.494 140,95 919,03 650
1.517.987
Universitas Sumatera Utara
� = � ∑ �. ��� − ∑ � ∑ ���
� ∑ �
2
− ∑ �
2
� = 12 × 919,03
− 78 × 140,95 12 × 650
− 78
2
= −0,0200135
ln � =
∑ ��� − � ∑ � �
= 11,614 � = 110.713,2
�
′
= ��
��
�
′
= 110.713,2 �
−0,0200135 �
�
′
= 110.713,2 �
−0,0200135 1
= 112.964,95 ≈ 112.965
���� =
∑ |
��
�
|
� �=1
�
=
1,357 12
= 11,24
2. Metode Kuadratis
KUADRATIS t
y t²
t³ t
⁴ ty
t²y t
yt 1
101.850 1
1 1
101.850 101.850
13
102.712
2
110.329 4
8 16
220.658 441.315
14
111.130
3 119.021
9 27
81 357.063
1.071.189 15
118.408
4 143.705
16 64
256 574.820
2.299.280 16
124.547
5
115.259 25
125 625
576.293 2.881.463
17
129.548
6 124.025
36 216
1.296 744.150
4.464.900 18
133.409
7 115.372
49 343
2.401 807.602
5.653.216 19
136.130
8
142.395 64
512 4.096
1.139.160 9.113.280
20
137.713
9 191.647
81 729
6.561 1.724.819
15.523.367 21
138.157
10 122.280
100 1.000
10.000 1.222.795
12.227.950 22
137.461
11
105.624 121
1.331 14.641
1.161.864 12.780.504
23
135.626
12 145.989
144 1.728
20.736 1.751.862
21.022.344 24
132.653
78 1.537.494
650 6.084
60.710 10.382.935
87.580.657 222
1.537.494
� = �� �
2
�
2
− � � �
4
� = 650
2
− 12 × 60.710 = −306.020 � = � � � � − � � ��
� = 78 × 1.537.494 − 12 × 10.382.935 = −4.670.724 � = � �
2
� � − � � �
2
� � = 650 × 1.537.494 − 12 × 87.580.657 = −51.597.106
Universitas Sumatera Utara
� = � � � �
2
− � � �
3
� = 78 × 650 − 12 × 6.084 = −22.308 � = �� ��
2
− � � �
2
� = 78
2
− 12 × 650 = −1.716 � =
�� −�� �� −�
2
= 10126,336 � =
�−�� �
= -569,574 � =
∑ �−� ∑ �−� ∑ �
2
�
= 93155,227 �
′
= � + �� + ��
2
�
′
= 93155,227 + 9.498,714 � + −608,1283�
2
�
′
= 93155,227 + 9.498,7141 + −608,12831
2
=
102.711,99
≈
102.712
���� =
∑ |
��
�
|
� �=1
�
=
1,35 12
= 11,21
Metode Terpilih: Kuadratis
Verifikasi Peramalan
y yt
e=y-yt |MR|
UCL LCL
101.850 102.712 -862
- 65.490,63 -65.490,63
110.329 111.130 -801
61,14 65.490,63 -65.490,63
119.021 118.408 613
1.413,79 65.490,63 -65.490,63
143.705 124.547 19.158 18.544,69 65.490,63 -65.490,63 115.259 129.548 -14.289 33.446,67 65.490,63 -65.490,63
124.025 133.409 -9.384
4.905,48 65.490,63 -65.490,63
115.372 136.130 -20.759 11.375,12 65.490,63 -65.490,63 142.395 137.713
4.682 25.440,53 65.490,63 -65.490,63
191.647 138.157 53.490 48.807,93 65.490,63 -65.490,63
Universitas Sumatera Utara
y yt
e=y-yt |MR|
UCL LCL
122.280 137.461 -15.182 68.671,42
65.490,63 -65.490,63 105.624 135.626 -30.002
14.820,77 65.490,63 -65.490,63
145.989 132.653 13.336 43.338,38
65.490,63 -65.490,63 270.825,91
-80.000 -60.000
-40.000 -20.000
20.000 40.000
60.000 80.000
P T
. JW
L
Peramalan Irawan 683 tahun 2016
Irawan 683 UCL
LCL
Universitas Sumatera Utara
PERAMALAN PRODUK IRAWAN 683-SP – PT. JWL
Irawan 682 Bulan
Demand
Januari
114.774
Februari
68.013
Maret
65.861
April
114.028
Mei
114.582
Juni
126.242
Juli
92.117
Agustus
78.888
September
101.747
Oktober
104.519
November
77.634
Desember
88.086
Total 1.146.490
Metode Peramalan Terpilih: •
Metode Kuadratis •