Nofi Yulianawati SKB Eksponential

  Nofi Yulianawati 04610219/E Studi Kelayakan Bisnis Metode Peramalan Penjualan (Simple Exponential)

  X

  PT.Yulia Jaya NO Tahun Penjualan

2 Log Y X log Y Log Y’

  1 1986 15000.00 -5 25.00 4.1761 -20.8805 4.1999 2 1987 16000.00 -4 16.00 4.2041 -16.8165 4.2107 3 1988 17000.00 -3

  9.00 4.2304 -12.6913 4.2215 4 1989 17500.00 -2 4.00 4.2430 - 8.4861 4.2323 5 1990 18000.00 -1 1.00 42553 - 4.2553 4.2430 6 1991 18500.00 0.00 4.2672 4.2538 7 1992 18500.00

  1 1.00 4.2672 4.2672 4.2646 8 1993 19000.00 2 4.00 4.2788 8.5575 4.2754 9 1994 19250.00 3 9.00 4.2844 12.8533 4.2862 10 1995 19500.00 4 16.00 4.2900 17.1601 4.2970 11 1996 19750.00 5 25.00 4.2956 21.4778 4.3078

  Jumlah 11 198000 110.00

  (Y) (X)

  1.19

  46.79 Y’= a + bX b = 436.36 a = 15818.18

  Y

  86

  = 42538 + 0.0108 ( -5 ) = 42537.94

  Y

  87 = 42538 + 0.0108 ( -4 )

  46.79

  = 42537.95 Y

  88 = 42538 + 0.0108 ( -3 )

  = 42537.976 Y = 42538 + 0.0108 ( -2 )

  89

  = 42537.97 Y

  90 = 42538 + 0.0108 ( -1 )

  = 42537.98 Y = 42538 + 0.0108 ( 0 )

  91

  = 42538 Y

  92 = 42538 + 0.0108 ( 1 )

  = 42538.01 Y

  93 = 42538 + 0.0108 ( 2 )

  = 42538.02 Y = 42538 + 0.0108 ( 3 )

  94

  = 42538.03 Y

  95 = 42538 + 0.0108 ( 4 )

  = 425381.04 Y = 42538 + 0.0108 ( 5 )

  96

  = 425381.05

1. Kuadrat Terkecil

  2 Dapat di rumuskan dengan :

   ( Y-Y’ ) NO Tahun Penjualan (Y)

  Exponential Y’ ( Y-Y’)^2 1 1986 15000.00 42537.94 758338139.4

  2 1987 16000.00 42537.95 704262790.2 3 1988 17000.00 42537.96 652187401 4 1989 17500.00 42537.97 626899941.7 5 1990 18000.00 42537.98 602112462.5 6 1991 18500.00 42538 577825444 7 1992 18500.00 42538.01 577825924.8 8 1993 19000.00 42538.02 554038385.5 9 1994 19250.00 42538.03 542332341.3

  10 1995 19500.00 425381.04 1.6473941 11 1996 19750.00 425381.05 1.6453654 Jumlah 11 198000.00 1233603.95 5595822834

  Jadi, Hasil kuadrat terkecil untuk metode Exponential = 5595822834 2. Metode Kesalahan Rata-rata Mutlak.

  Dapat dirumuskan dengan :  Y – Y’

  AAE = __________ N

  Keterangan : AAE = Average Absolute Error Y = Data riil ( Penjualan riil ) Y’ = Data ramalan N = Jumlah periode / waktu dari data ramalan   = Harga mutlak

• 1035603.95 AAE = __________

  11

  

C. Metode Kesalahan Kuadrat Rata-rata Akar ( Root Mean Squared Error )

  Dapat dirumuskan dengan :

  2

   ( Y – Y’ ) RASE = ______________

  N Keterangan :

  RASE = Root Average Squared Error Y = Data riil Y’ = Data ramalan N = Jumlah waktu data ramalan

  5595822834 RASE = ______________

  11 = 6800.475697 = 82.4649968

  D. Korelasi

  Dapat dirumuskan dengan :

  2

   ( Y-Y’ ) r = 1- _______

  2

   ( Y - Y) Keterangan : r = Koefisien korelasi Y = Data riil Y’ = Data peramalan

  Y = Means data riil =

  Y N

  = 198000.00

  11 = 18000

  5595822834 r = 1- _______

  3.24 = 1 – 1727105813

  = 0