End-user experience is important for any IT system. Every SAP project spends some of its budget on activities to ensure that response times are snappy and the system doesn’t slow to a crawl on heavy-usage days.
Projects often engage SAP’s Volume Test Optimization (VTO) service to help improve system performance under load. The VTO team works with the project’s performance tester during this exercise. As this service is quite expensive, it is in everyone’s best interests to work together effectively to get the best value from this activity.
There are 3 SAP MaxAttention services that are important for system performance. These are:
- Technical Integration Check (TIC). The SAP team will check the interconnections between the SAP components, and with external systems. This service also includes a design review, covering architecture, hardware sizing, patch levels/versions, etc. There is no need for support from the performance tester for this exercise.
- Business Process Performance Optimization (BPPO). The aim of this exercise is to identify individual business processes or transactions that are slow or consume excessive system resources (memory, etc.). Performance is not measured under load, but the load testing scripts can still be used to exercise the system with a single user to generate metrics to be analysed by the BPPO team.
- Volume Test Optimization (VTO). During VTO, the system is observed while under peak load and tuning changes are suggested (code changes should have already been suggested during BPPO). This is generally done towards the end of the Build phase, when the system is functionally complete.
The VTO team will typically be composed of 4 or 5 technical specialists, covering each of the system components or areas of responsibility (e.g. Fiori, HANA, Basis, ABAP, etc). The service may be 100% remote, or a combination of people working remotely and on-site. The service generally takes three days, and produces a report with recommendations at the end.
The VTO team does not have the capability of generating load – they observe the system while load is running, and provide tuning recommendations. Load must be generated by the project’s performance tester. This brings together the complementary skills of performance testing and performance tuning
Obviously the peak load test must be prepared and ready to run when the VTO team arrives, but to really get the most value from the VTO service, a complete performance test cycle must have already been completed, with the aim of finding and fixing as many defects as possible before VTO starts. VTO’s time is best spent on problems that the project has struggled to fix, rather than on simple problems. Three days is a very short time to diagnose and fix issues, so it is best to be very focussed.
Ideally the VTO report will say “the system is able to support expected user volumes, but there are some minor improvements to be made”, getting a failing report from VTO can lead to project delays and another round of VTO.