Hi:
Here are a couple of scenarios for illustration purposes.
1) you work for a company and there are 100 business analysts. Every analyst is responsible for a different Product (or country or region or -something). Do you make 100 stored processes -- one for each analyst, or do you make 1 stored process with a parameter that allows each analyst to select -their- product? Part of the power of parameters in a stored process is that you can use the data itself to provide a parameter list in a drop down box -- so the analyst can just pick from a list.
2) You work for a company that does forecasting. The basic statistical analysis always uses the same STAT procedure -- the only thing that changes are some of the options that control the STAT procedure and perhaps the time period of data being analyzed. Do you make a stored process for every possible combination of options and dates, or make a stored process which shows the 'changeable' options for the STAT procedure and allows the analyst/forecaster to select the date range of the data??
If you perform a Google search on SAS stored processes and parameters, I'm sure you will find many user group papers that talk about how to set and use parameters.
Even if you do NOT use SAS Stored Processes, the Parameter Manager in SAS EG is a powerful tool which allows you to make your projects and tasks more flexible. Again, a Google search on Enterprise Guide and Parameter Manager may provide you with some user group papers on the subject.
SAS Stored Processes and EG parameters are both tapping into the underlying power of the SAS Macro facility. For an overall introduction to the SAS Macro facility, I find that this is a good paper:
http://www2.sas.com/proceedings/sugi28/056-28.pdf
cynthia