Seasonality Forecasting

[Basil]

I am working on a seasonality project and I would like to determine a monthly affect if possible. I found a graph at:

http://support.sas.com/rnd/app/ets/cap/ets_forecasting.html

which sort of shows the seasonality trend I am looking for. I have tried using the forecast command: "%fcb" and I am able to come up with a logistic forecast. It is smooth and does not include the jumps per month. I would like a graph that really shows the monthly affect and not just the yearly slope. (I have set my interval to month). I am fairly new to SAS, any suggestions?

[Kabuto]

Whether your data have monthly effect is determined by ACF and PACF which don't show in your link, but they are absolutely necessary before fitting a time series model. The Time Series Forecasting System has this function. I guess there are two possible reasons in your study. First, your data really have no monthly trend. Second, the time series model you fit is not appropriate.