Typically End of life period for hardware will be 5 years and software will be 2 yrs (It may differ vendor to vendor and depends on organization policy). SAP EOL policy is different from other softwares. It spans 3 or more years for software and extend the support for hardware in coordination with hardware partenrs. SAP policy for End of Patch, End of Maintenance, and End of life (support) is available and it is well monitored with solution manager maintenance tool. For example EOL for SAP BusinessObjects XI 3.1: December 31, 2015 this is the date that patch support will end. It is scheduled to reach End of Priority-One Support on December 31, 2017. For End of Life - Support (Product) cases customers should explore the migration options with their SAP Sales Account Executives.