Ariba will support 9r1 for as long as we support the Ariba On-Premise product or provide a new major version. Support for 9r1 will be via Hot Fixes on 9r1 Service Pack 30 for selected S1 issues. Ariba does not address every 9r1 S1 issue via a Hot Fix on 9r1. Instead, Ariba may choose to address a 9r1 S1 defect in a Service Pack on a future point release and in those circumstances the customer is required to upgrade to that Point Release and Service Pack to obtain the defect resolution.
There are no plans to end-of life the on-premise product and customers can always sign a TSS for up to 3 years.