Here is an option:
1. Go to SE38
2. Enter "RSPROCESS" for the program name
3. Choose the radio button "Variants" under subobjects section of SE38
4. Click on "Display" button
5. In ABAP Variants screen enter variants name and click on create
6. In the u201Cmaintain variantu201D screen enter "chain" for "Process Type". In the field "Process Variant" enter your processchain name.
7. Then go to sm36 to create SM37 job. Enter a job name (can your pc name)
8. Go to "Step" button in SM36. Enter "RSPROCESS" for the ABAP program name and enter the variant name you created for variant, click on check
9. In sm36 screen click on "start condition" and give the appropriate start condition and check.
10. in sm36 screen click on "save" button.
This will schedule and execute the processchain according to the start condition value specified in sm36.
In some environments you would not have authorization to change a processchian in QA or production.
If you need to schedule a processchain on demand (which requires to change start variant of the chain), you can use execute PC via SM37.
I had to do this in the past with numerous clients I worked with.