What type of SAS environment (local install, remote server) and OS platform (IBM mainframe, Windows workstation/server, *nix) are you using? These are important considerations. In most environments, you can launch SAS as a background/batch type of event, likely using a "scheduling utility" program for your particular SAS OS environment.
Suggest you review the "companion" guide for the particular OS platform where you run SAS for more details. Also, this topic has been discussed in these forums previously - always suggesting to search the archives before posting. The SAS-hosted DOC and supplemental technical / conference reference material is available at the SAS support http://support.sas.com/ website.