5.2.4. Perhitungan Jumlah Permintaan Setiap Minggu Distribution Center
Perhitungan jumlah permintaan setiap minggu dari setiap distribution center diperoleh dengan melakukan pembagian antara jumlah permintaan setiap
distribution center pada setiap bulannya dengan jumlah minggu yang ada pada setiap bulannya. Jumlah permintaan distribution center untuk setiap minggu dapat
dilihat pada Tabel 5.22.
Tabel 5.22. Jumlah Permintaan Distribution center Setiap Minggu
Periode Jumlah
Minggu Jumlah Permintaan Distribution Center DC
Medan Tanjung Morawa
Siantar Tebing Tinggi
Batang PipaBulan
Batang PipaMinggu
Batang PipaBulan
Batang PipaMinggu
Batang PipaBulan
Batang PipaMinggu
Batang PipaBulan
Batang PipaMinggu
Januari 5
277 55
74 15
105 21
97 19
Februari 4
296 74
91 23
110 27
89 22
Maret 4
213 53
84 21
118 30
44 11
April 4
307 77
69 17
85 21
81 20
Mei 5
113 23
64 13
64 13
103 21
Juni 4
53 13
72 18
51 13
74 19
Juli 5
11 2
65 13
49 10
30 6
Tabel 5.22. Jumlah Permintaan Distribution center Setiap Minggu Lanjutan
Periode Jumlah
Minggu Jumlah Permintaan Distribution Center DC
Medan Tanjung Morawa
Siantar Tebing Tinggi
Batang PipaBulan
Batang PipaMinggu
Batang PipaBulan
Batang PipaMinggu
Batang PipaBulan
Batang PipaMinggu
Batang PipaBulan
Batang PipaMinggu
Agustus 4
17 4
56 14
42 11
49 12
September 4
44 11
58 14
49 12
61 15
Oktober 5
111 22
75 15
67 13
52 10
November 4
153 38
77 19
100 25
28 7
Desember 4
397 99
71 18
101 25
61 15
Total 52
1.990 472
855 200
940 221
770 178
Sumber : Pengolahan Data
5.2.5. Distribution Resource Planning worksheet
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Dari perhitungan data diatas, maka dapat disusun perencanaan DRP untuk setiap DC dalam time bucket mingguan sebab lead time masing-masing DC tidak
melewati satu bulan atau hanya dalam mingguan. Dalam distribution resource planning worksheet terdapat beberapa istilah
yang perlu diketahui, yaitu : 1.
On Hand Balance adalah jumlah persediaan awal produk yang ada pada distribution center.
2. Safety Stock adalah persediaan untuk melindungi atau menjaga kemungkinan
terjadinya kekurangan produk. 3.
Lead Time adalah waktu yang diperlukan dalam pelepasan order sampai order diterima di stock room pada distribution center.
4. Order Quantity adalah jumlah produk yang dikirimkan ke untuk setiap kali
pemesanan. 5.
Demands Forecast adalah peramalan jumlah permintaan dari masing-masing distribution center.
6. In Transit adalah jumlah produk yang sedang dalam proses pendistribusian.
7. Projected On Hand adalah persediaan yang ada dan siap digunakan.
8. Planned Shipments-Receipt Date adalah jadwal perencanaan penerimaan
produk yang dikirim. 9.
Planned Shipments-Ship Date adalah jadwal perencanaan pengiriman produk. Berikut contoh langkah-langkah pengisian Distribution Resource
Planning Worksheet pada Distribution center Medan adalah :
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1. On Hand Balance = 225 Status persediaan awal DC Medan, diperoleh dari
Tabel 5.4. 2.
Lead Time = 2 hours ≈ 0 week Lead Time pendistribusian produk dari CSF ke DC Medan, diperoleh dari Tabel 5.3.
3. Order Quantity = 110 batang diperoleh dari Tabel 5.20.
4. Safety Stock = 214 batang diperoleh dari Tabel 5.21.
5. Projected On Hand Past Due = 225 Batang diperoleh dari On Hand
Balance 6.
Demands Forecast 1
st
Week = 55 Batang diperoleh dari Tabel 5.22. 7.
In Transit 1
st
Week = 0, tidak adanya produk yang sedang dalam proses pengiriman
8. Planned Shipments-Receipt Date = 110 Batang diperoleh dari Order
Quantity 9.
Planned Shipments-Ship Date = 110 Batang diperoleh dari Order Quantity 10.
Project On Hand 1
st
Week = Project On Hand Past Due + Order Quantity - Demands Forecast 1
st
Week = 225 + 110 – 55 = 280 Batang.
11. Demands Forecast 2
nd
Week = 55 Batang diperoleh dari Tabel 5.22. 12.
Project On Hand 2
nd
Week = Project On Hand 1
st
Week - Demands Forecast 2
nd
Week = 280 – 55 = 224 Batang
13. Demands Forecast 3
rd
Week = 55 Batang diperoleh dari Tabel 5.22. 14.
In Transit 3
rd
Week = 0, tidak adanya produk yang sedang dalam proses pengiriman
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15. Planned Shipments-Ship Date 3
rd
Week = 110 Batang diperoleh dari Order Quantity
16. Planned Shipments-Receipt Date 3
rd
Week = 110 Batang diperoleh dari Order Quantity
17. Project On Hand 3
rd
Week = Project On Hand 2
nd
Week + Order Quantity - Demands Forecast 3
rd
Week = 224 + 110 – 55 = 279 Batang
18. Dilakukan hal yang sama hingga minggu ke 52 sehingga Distribution
Resource Planning Worksheet untuk Distribution center Sakura Jaya terisi keseluruhan.
Distribution Resource Planning Worksheet untuk masing-masing distribution center dapat dilihat pada Tabel 5.23 hingga Tabel 5.26.
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Tabel 5.23. Distribution Resource Planning Sheet untuk DC Medan
Distribution Resource Planning Sheet untuk Distribution Center Medan On Hand Balance
225 Lead Time
3 hours ≈ 0 week
Safety Stock 214
Order Quantity 110
Distribution Center Medan
Past Due
Week 1
2 3
4 5
6 7
8 9
10 11
12 13
Demands Forecast 55
55 55
55 55
74 74
74 74
53 53
53 53
In Transit Projected on Hand
225 280
224 279
223 278
314 240
276 312
259 316
263 319
Planned Shipments - Receipt Date 110
110 110
110 110
110 110
110
Planned Shipments - Ship Date 110
110 110
110 110
110 110
110
Past Due
Week 14
15 16
17 18
19 20
21 22
23 24
25 26
Demands Forecast 77
77 77
77 23
23 23
23 23
13 13
13 13
In Transit Projected on Hand
319 243
276 309
232 320
297 274
252 229
216 313
299 286
Planned Shipments - Receipt Date 110
110 110
110
Planned Shipments - Ship Date 110
110 110
110
Past Due
Week 27
28 29
30 31
32 33
34 35
36 37
38 39
Demands Forecast 2
2 2
2 2
4 4
4 4
11 11
11 11
In Transit Projected on Hand
286 284
282 280
278 275
271 267
263 259
248 237
226 215
Planned Shipments - Receipt Date Planned Shipments - Ship Date
Past Due
Week 40
41 42
43 44
45 46
47 48
49 50
51 52
Demands Forecast 22
22 22
22 22
38 38
38 38
99 99
99 99
In Transit Projected on Hand
215 303
281 259
237 215
287 248
320 282
293 303
314 215
Planned Shipments - Receipt Date 110
110 110
110 110
110
Planned Shipments - Ship Date 110
110 110
110 110
110
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Tabel 5.24. Distribution Resource Planning Sheet untuk DC Tanjung Morawa
Distribution Resource Planning Sheet untuk Distribution Center Tanjung Morawa On Hand Balance
37
Lead Time
3 hours ≈ 0 week
Safety Stock 17
Order Quantity 70
Distribution Center Tanjung Morawa
Past Due
Week 1
2 3
4 5
6 7
8 9
10 11
12 13
Demands Forecast 15
15 15
15 15
23 23
23 23
21 21
21 21
In Transit Projected on Hand
37 22
77 62
48 33
80 57
35 82
61 40
19 68
Planned Shipments - Receipt Date 70
70 70
70
Planned Shipments - Ship Date 70
70 70
70
Past Due
Week 14
15 16
17 18
19 20
21 22
23 24
25 26
Demands Forecast 17
17 17
17 13
13 13
13 13
18 18
18 18
In Transit Projected on Hand
68 50
33 86
69 56
43 31
18 75
57 39
21 72
Planned Shipments - Receipt Date 70
70 70
Planned Shipments - Ship Date
70 70
70
Past Due
Week 27
28 29
30 31
32 33
34 35
36 37
38 39
Demands Forecast
13 13
13 13
13 14
14 14
14 14
14 14
14
In Transit Projected on Hand
72 59
46 33
20 77
63 49
35 21
76 62
47 33
Planned Shipments - Receipt Date 70
70
Planned Shipments - Ship Date 70
70
Past Due
Week 40
41 42
43 44
45 46
47 48
49 50
51 52
Demands Forecast 15
15 15
15 15
19 19
19 19
18 18
18 18
In Transit Projected on Hand
33 18
72 57
42 27
77 58
39 20
72 54
36 18
Planned Shipments - Receipt Date 70
70 70
Planned Shipments - Ship Date
70 70
70
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Tabel 5.25. Distribution Resource Planning Sheet untuk DC Siantar
Distribution Resource Planning Sheet untuk Distribution Center Siantar On Hand Balance
75 Lead Time
4 hours ≈ 0 week
Safety Stock 46
Order Quantity 70
Distribution Center Siantar
Past Due Week
1 2
3 4
5 6
7 8
9 10
11 12
13 Demands Forecast
21 21
21 21
21 27
27 27
27 30
30 30
30
In Transit Projected on Hand
75 54
104 83
62 111
84 56
99 72
113 83
54 95
Planned Shipments - Receipt Date 70
70 70
70 70
Planned Shipments - Ship Date 70
70 70
70 70
Past Due Week
14 15
16 17
18 19
20 21
22 23
24 25
26 Demands Forecast
21 21
21 21
13 13
13 13
13 13
13 13
13
In Transit Projected on Hand
95 73
52 101
80 67
54 112
99 87
74 61
48 106
Planned Shipments - Receipt Date 70
70 70
Planned Shipments - Ship Date 70
70 70
Past Due Week
27 28
29 30
31 32
33 34
35 36
37 38
39 Demands Forecast
10 10
10 10
10 11
11 11
11 12
12 12
12
In Transit Projected on Hand
106 96
86 77
67 57
46 106
96 85
73 61
49 107
Planned Shipments - Receipt Date 70
70
Planned Shipments - Ship Date
70 70
Past Due Week
40 41
42 43
44 45
46 47
48 49
50 51
52 Demands Forecast
13 13
13 13
13 25
25 25
25 25
25 25
25
In Transit Projected on Hand
107 94
80 67
54 111
86 61
107 82
56 102
76 51
Planned Shipments - Receipt Date 70
70 70
Planned Shipments - Ship Date 70
70 70
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Tabel 5.26. Distribution Resource Planning Sheet untuk DC Tebing Tinggi
Distribution Resource Planning Sheet untuk Distribution Center Tebing Tinggi On Hand Balance
48 Lead Time
3 hours ≈ 0 week
Safety Stock 41
Order Quantity 68
Distribution Center Tebing Tinggi
Past Due Week
1 2
3 4
5 6
7 8
9 10
11 12
13 Demands Forecast
19 19
19 19
19 22
22 22
22 11
11 11
11
In Transit Projected on Hand
48 97
77 58
107 87
65 43
89 67
56 45
103 91
Planned Shipments - Receipt Date 68
68 68
68
Planned Shipments - Ship Date 68
68 68
68
Past Due Week
14 15
16 17
18 19
20 21
22 23
24 25
26 Demands Forecast
20 20
20 20
21 21
21 21
21 19
19 19
19
In Transit Projected on Hand
91 71
51 99
79 58
106 86
65 44
94 76
57 107
Planned Shipments - Receipt Date 68
68 68
68
Planned Shipments - Ship Date 68
68 68
68
Past Due Week
27 28
29 30
31 32
33 34
35 36
37 38
39 Demands Forecast
6 6
6 6
6 12
12 12
12 15
15 15
15
In Transit Projected on Hand
107 101
95 89
83 77
65 53
109 97
81 66
51 104
Planned Shipments - Receipt Date 68
68
Planned Shipments - Ship Date 68
68
Past Due Week
40 41
42 43
44 45
46 47
48 49
50 51
52 Demands Forecast
10 10
10 10
10 7
7 7
7 15
15 15
15
In Transit Projected on Hand
104 93
83 72
62 52
45 106
99 92
77 61
46 99
Planned Shipments - Receipt Date 68
68
Planned Shipments - Ship Date 68
68
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5.2.6. Perhitungan Frekuensi Pemesanan
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