exportServiceInstance will export the RPD, Presentation Catalog, and Security model (application roles & policies etc – but not WLS LDAP) into a single .bar file, from which they can be imported to another environment, or restored to the same one at a later date (e.g. for backup/restore). To run exportServiceInstance you need to launch WLST first. The following demonstrates how to call it, and embeds the current timestamp & machine details in the backup (useful info, and also makes the backup name unique each time).