PERAMALAN PRODUK IRAWAN 683 – PT. BWP
Irawan 683 Bulan
Demand
Januari
48.500
Februari
56.390
Maret
43.722
April
66.595
Mei
57.629
Juni
53.556
Juli
65.082
Agustus
49.191
September
66.085
Oktober
26.583
November
30.807
Desember
49.581
Total 613.721
Metode Peramalan Terpilih: •
Metode Linier •
Metode Kuadratis
1. Metode Linier
LINIER t
y ty
t² t
yt 1
48.500 48.500
1 13
57.964
2 56.390
112.781 4
14 56.724
3
43.722 131.166
9 15
55.484
4 66.595
266.380 16
16 54.244
5 57.629
288.146 25
17 53.004
6 53.556
321.338 36
18 51.763
7
65.082 455.571
49 19
50.523
8 49.191
393.528 64
20 49.283
9 66.085
594.765 81
21 48.043
10 26.583
265.825 100
22 46.803
11
30.807 338.877
121 23
45.563
12 49.581
594.972 144
24 44.323
78 613.721 3.811.848 650 222 613.721
Universitas Sumatera Utara
� = � ∑ �� − ∑ � ∑ �
� ∑ �
2
− ∑ �
2
� = 12 × 3.811.848
− 78 × 613.712 12 × 650
− 78
2
= −1.240,119
� = ∑ � − � ∑ �
� � =
613.721— 1.240,119 × 78 12
12 = 59.204,174 �′ = � + ��
�
′
= 59.204,174 + −1.240,119�
�
′
= 59.204,174 + −1.240,1191 = 57.964,05 ≈ 57.964
���� =
∑ |
��
�
|
� �=1
�
=
2,61 12
= 21,78
2. Metode Kuadratis
KUADRATIS t
y t²
t³ t
⁴ ty
t²y t
yt 1
48.500 1
1 1
48.500 48.500
13 49.443
2
56.390 4
8 16
112.781 225.561
14 52.851
3 43.722
9 27
81 131.166
393.498 15
55.329
4 66.595
16 64
256 266.380
1.065.520 16
56.877
5
57.629 25
125 625
288.146 1.440.731
17 57.496
6 53.556
36 216
1.296 321.338
1.928.025 18
57.186
7 65.082
49 343
2.401 455.571
3.188.994 19
55.946
8 49.191
64 512
4.096 393.528
3.148.224 20
53.776
9 66.085
81 729
6.561 594.765
5.352.885 21
50.677
10 26.583
100 1.000 10.000 265.825
2.658.250 22
46.648
11
30.807 121 1.331 14.641
338.877 3.727.647
23 41.690
12 49.581
144 1.728 20.736 594.972
7.139.664 24
35.802
78 613.721 650 6.084 60.710 3.811.848 30.317.499 222 613.721
� = �� �
2
�
2
− � � �
4
� = 650
2
− 12 × 60.710 = −306.020 � = � � � � − � � ��
� = 78 × 613.721 − 12 × 3.811.848 = 2.128.046 � = � �
2
� � − � � �
2
�
� = 650 ×
613.7217
− 12 × 30.317.499 = 35.108.503
Universitas Sumatera Utara
� = � � � �
2
− � � �
3
� = 78 × 650 − 12 × 6.084 = −22.308 � = �� ��
2
− � � �
2
� = 78
2
− 12 × 650 = −1.716 � =
�� −�� �� −�
2
= 4.802,015 � =
�−�� �
= -464,779 � =
∑ �−� ∑ �−� ∑ �
2
�
= 45.105,857 �
′
= � + �� + ��
2
�
′
= 45.105,857 + 4.802,015 � + −464,779�
2
�
′
= 45.105,857 + 4.802,015 1 + −464,7791
2
= 49.443,09 ≈ 49.443
���� =
∑ |
��
�
|
� �=1
�
=
2,42 12
= 20,14
Metode Terpilih: Kuadratis
Verifikasi Peramalan
y yt
e=y-yt |MR|
UCL LCL
48.500
49.443
-943 -
41.132,90 -41.132,90
56.390 52.851
3.539 4.482,57
41.132,90 -41.132,90
43.722 55.329
-11.607 15.146,37
41.132,90 -41.132,90
66.595 56.877
9.718 21.324,44
41.132,90 -41.132,90
57.629
57.496
133 9.584,75
41.132,90 -41.132,90
53.556 57.186
-3.630 3.762,44
41.132,90 -41.132,90
65.082 55.946
9.136 12.765,37
41.132,90 -41.132,90
49.191 53.776
-4.585 13.720,82
41.132,90 -41.132,90
66.085
50.677
15.408 19.993,24
41.132,90 -41.132,90
26.583 46.648
-20.066 35.473,70
41.132,90 -41.132,90
30.807 41.690
-10.883 9.182,86
41.132,90 -41.132,90
49.581 35.802
13.779 24.661,92
41.132,90 -41.132,90
170.098,48
Universitas Sumatera Utara
-50.000 -40.000
-30.000 -20.000
-10.000 10.000
20.000 30.000
40.000 50.000
P T
. B
W P
Permintaan Irawan 683 tahun 2016
Irawan 683 UCL
LCL
Universitas Sumatera Utara
PERAMALAN PRODUK IRAWAN 683-SP – PT. BWP
Irawan 683-SP Bulan
Demand
Januari
68.244
Februari
43.281
Maret
33.775
April
77.136
Mei
67.574
Juni
95.638
Juli
68.345
Agustus
39.444
September
77.081
Oktober
61.182
November
37.870
Desember
83.053
Total 752.622
Metode Peramalan Terpilih: •
Metode Eksponensial •