Who hasn’t heard one of these stories: A company runs SAP solutions for their critical business processes and although they should for some reason they don’t upgrade because they are afraid of effort and down-time. While effort has been addressed through a number of measures in the past, the required down-time caused constant threat to the SAP customer base. But there may be relief on the horizon as SAP has recently released nZDM – Near Zero Downtime Maintenance for some solutions. And the best news is it comes at no additional cost for customers using SAP Software Update Manager!
One reason why down-times during upgrade have gained additional importance is the fact that business became faster in general and that SAP solutions are being used more and more for business processes I would call “executional”. Examples could be anything from posting goods movements, real-time warehousing, or production execution. As often seen with multi-national companies there is no time-slot found where business could calm down across all subsidiaries – so during upgrade at least some facilities would have to deal with system down-times during their business hours. It’s obvious they want to minimize the impact of upgrade – and a significant reduction of down-time would come very handy.
The concept of nZDM is based on the fact that during upgrade users need to access different data objects than the upgrade process which means it can be processed in parallel to certain extend. An example: Users may use applications like creating sales orders and in consequence they access and change data of tables of the sales application. But users won’t change DDIC objects and usually they are not meant to change customizing tables during daily operation. But exactly the latter is the target during upgrade. To avoid inconsistency it needs to identify exactly what needs to be blocked for the upgrade procedure, but all other element can still be used – resulting in lower down-time!
Obviously there are phases during upgrade which cannot be addressed with this concept. Cool down period, but also validation and ramp-up will still take their share, but the required time for technical downtime and transports could be reduced for example by 70% (installation of ERP EhP in 2013, measured before and after nZDT), and the “business downtime” was reduced by 53%.
In the meantime nZDM is available for ABAP-based solutions like SAP ERP, SAP EWM, but also SAP PI. It is available for SAP Enterprise Portal and it’s planned for more solutions for more solutions to come. ZDM is still under development and future releases may allow for further reduction of downtime, so stay tuned!
Further readings available in SAP SCN: