Antje, In addition to all the excellent advice you have been given, make sure that you have adequate levels of load and performance testing, as well a strong release/change management processes in place. Without this, your 24x7 website WILL have issues regardless of the way you manage outage: without load testing on similar or scaled down hardware and a clear understanding of what changed and when it was changed, and how it is communicated and managed, your organization is setting itself up for disaster... And of course, all of this will take lots of time, talent and money! So make sure your management understands that adding a single 9 to the uptime of 99.9% logarithmically increases cost. -- John Kanagaraj <>< DB Soft Inc http://www.linkedin.com/in/johnkanagaraj http://jkanagaraj.wordpress.com (Sorry - not an Oracle blog!) ** The opinions and facts contained in this message are entirely mine and do not reflect those of my employer or customers ** -- //www.freelists.org/webpage/oracle-l