Predicting Sales Values Using PROC ARIMA

[r0sner]

Hey SAS Community,

I am new to SAS and would appreciate any advice on this topic.

For a university project, I need to calculate the expected sales value for the upcoming months after my dataset runs out. The dataset includes Total_amt, which contains the transaction values, and Tran_date, which specifies the dates of the transactions.

data TransactionsWithSasDate;
set Transactions;
Tran_date = mdy(Month, Day, Year);
format Tran_date date9.;
run;

proc sql;
create table MonthlySales as
select 
intnx('Month', Tran_date, 0, 'Beginning') as Month format=date9., 
sum(Total_amt) as MonthlySalesValue
from TransactionsWithSasDate
group by calculated Month;
quit;

proc arima data=MonthlySales;
identify var=MonthlySalesValue(12);
estimate p=1 q=1;
forecast lead=12 id=Month interval=Month out=ForecastedSalesValue;
run;

proc sgplot data=ForecastedSalesValue;
series x=Month y=MonthlySalesValue / lineattrs=(color=blue) legendlabel="Actual";
series x=Month y=Forecast / lineattrs=(color=red) legendlabel="Forecast";
xaxis label='Month';
yaxis label='Monthly sales value';
title 'Monthly Sales Trend and Forecast';
run;

 

I double-checked my code, but I am not sure if it is correct because the output graph looks a little off.

Any advice on this topic would be highly appreciated!

Greetings, Johannes

[sbxkoenk]

---

@r0sner wrote: 

I double-checked my code, but I am not sure if it is correct because the output graph looks a little off.

Any advice on this topic would be highly appreciated!

Greetings, Johannes

---

Your first and last month (of actual sales -- blue line) make a good model and a good forecast almost impossible.

The last month is presumably incomplete (half-month sales?)

and the first month is either incomplete or still part of ramp-up during a product launch (new product introduction).

BR,
Koen

[Ksharp]

You'd better post it at right forum:
Forecasting Forum
https://communities.sas.com/t5/SAS-Forecasting-and-Econometrics/bd-p/forecasting_econometrics

[sbxkoenk]

I moved this topic thread to "SAS Forecasting and Econometrics" - board.