Hello,

I am a total newbie at forecasting and have a question about the forecasting function.

I have three months worth of sales data for 8 SKUs. I need to predict the next six months of sales for these SKUs. Would the =FORECAST(x, known_y's, known_x's) function work for me here?

Here's the set up I have with some dummy numbers. So I need to predict April to Sept-17 sales data:

SKU Jan-17 Feb-17 Mar-17 Apr-17 May-17 Jun-17 Jul-17 Aug-17 Sep-17
1 1,111 2,222 3,333
2 2,222 3,333 4,444
3 3,333 4,444 5,555
4 4,444 5,555 6,666
6 5,555 6,666 7,777
7 6,666 7,777 8,888
8 7,777 8,888 9,999

I used the =FORECAST(x, known_y's, known_x's) function to get the following answers:

SKU Jan-17 Feb-17 Mar-17 Apr-17 May-17 Jun-17 Jul-17 Aug-17 Sep-17
1 1,111 2,222 3,333 4480 5646 6775 7942 9108 10237
2 2,222 3,333 4,444 5591 6757 7886 9053 10219 11348
3 3,333 4,444 5,555 6702 7868 8997 10164 11330 12459
4 4,444 5,555 6,666 7813 8979 10108 11275 12441 13570
6 5,555 6,666 7,777 8924 10090 11219 12386 13552 14681
7 6,666 7,777 8,888 10035 11201 12330 13497 14663 15792
8 7,777 8,888 9,999 11146 12312 13441 14608 15774 16903


These are the formulas behind the numbers:

SKU 42766 =+EOMONTH(N2,1) =+EOMONTH(O2,1) =+EOMONTH(P2,1) =+EOMONTH(Q2,1) =+EOMONTH(R2,1) =+EOMONTH(S2,1) =+EOMONTH(T2,1) =+EOMONTH(U2,1)
1 1111 2222 3333 =FORECAST($Q$2,N3:P3,$N$2:$P$2) =FORECAST($R$2,$N3:$P3,$N$2:$P$2) =FORECAST($S$2,$N3:$P3,$N$2:$P$2) =FORECAST($T$2,$N3:$P3,$N$2:$P$2) =FORECAST($U$2,$N3:$P3,$N$2:$P$2) =FORECAST($V$2,$N3:$P3,$N$2:$P$2)
2 2222 3333 4444 =FORECAST($Q$2,N4:P4,$N$2:$P$2) =FORECAST($R$2,$N4:$P4,$N$2:$P$2) =FORECAST($S$2,$N4:$P4,$N$2:$P$2) =FORECAST($T$2,$N4:$P4,$N$2:$P$2) =FORECAST($U$2,$N4:$P4,$N$2:$P$2) =FORECAST($V$2,$N4:$P4,$N$2:$P$2)
3 3333 4444 5555 =FORECAST($Q$2,N5:P5,$N$2:$P$2) =FORECAST($R$2,$N5:$P5,$N$2:$P$2) =FORECAST($S$2,$N5:$P5,$N$2:$P$2) =FORECAST($T$2,$N5:$P5,$N$2:$P$2) =FORECAST($U$2,$N5:$P5,$N$2:$P$2) =FORECAST($V$2,$N5:$P5,$N$2:$P$2)
4 4444 5555 6666 =FORECAST($Q$2,N6:P6,$N$2:$P$2) =FORECAST($R$2,$N6:$P6,$N$2:$P$2) =FORECAST($S$2,$N6:$P6,$N$2:$P$2) =FORECAST($T$2,$N6:$P6,$N$2:$P$2) =FORECAST($U$2,$N6:$P6,$N$2:$P$2) =FORECAST($V$2,$N6:$P6,$N$2:$P$2)
6 5555 6666 7777 =FORECAST($Q$2,N7:P7,$N$2:$P$2) =FORECAST($R$2,$N7:$P7,$N$2:$P$2) =FORECAST($S$2,$N7:$P7,$N$2:$P$2) =FORECAST($T$2,$N7:$P7,$N$2:$P$2) =FORECAST($U$2,$N7:$P7,$N$2:$P$2) =FORECAST($V$2,$N7:$P7,$N$2:$P$2)
7 6666 7777 8888 =FORECAST($Q$2,N8:P8,$N$2:$P$2) =FORECAST($R$2,$N8:$P8,$N$2:$P$2) =FORECAST($S$2,$N8:$P8,$N$2:$P$2) =FORECAST($T$2,$N8:$P8,$N$2:$P$2) =FORECAST($U$2,$N8:$P8,$N$2:$P$2) =FORECAST($V$2,$N8:$P8,$N$2:$P$2)
8 7777 8888 9999 =FORECAST($Q$2,N9:P9,$N$2:$P$2) =FORECAST($R$2,$N9:$P9,$N$2:$P$2) =FORECAST($S$2,$N9:$P9,$N$2:$P$2) =FORECAST($T$2,$N9:$P9,$N$2:$P$2) =FORECAST($U$2,$N9:$P9,$N$2:$P$2) =FORECAST($V$2,$N9:$P9,$N$2:$P$2)

Is this an appropriate way to use the forecast function? Is my use of the month in question the right "x" (cells Q2, R2,S2, T2,U2, V2) and the months I have data for the right "known_x's" (N2:P2)?

I can send this excel sheet if that is helpful. I REALLY appreciate your help! Thank you!