— written by Heinz Feil, Head of internal IT, itelligence —
- What: conversion of our worldwide ERP systems to SAP HANA.
- When: Project start was in April, Go-Live is planned for October.
- Numberof countries involved: currently 19, eventually 21.
- Noteworthy aspects: all of our HR data are in the ERP system and not in a separate ERP for HR.
Test Phase “Wave 0”
In order to avoid nasty surprises during the actual conversion, we planned a detailed “Wave O” phase, in which we intended to answer the following questions:
- Are there technical challenges of which we were initially unaware? Because in the final analysis, before the conversion to HANA the replacement of our server and the migration from ERP 6.04 to ERP 6.06 are necessary.
- How large must the databank, and concurrently, the main memory be?
- How much in-house development (ABAP) must we be prepared to handle in order to get us in shape for HANA and to achieve the accelerations in the scanning?
- How long will the conversion take? Will one weekend be sufficient?
The following sequence emerges:
Thus, in April our ERP system was copied in a test environment. The release upgrade to ERP 6.06 took place without any problems. Here we were on familiar ground. The upgrade to 6.06 on HANA (also called 6.16) also occurred without any great difficulties. We continued with the migration to SAP HANA. Here, the first minor challenges arose. The migration stopped at double digits. So we sent two OSS Message reports, and were able to quickly deal with the mistake in cooperation with SAP.
In the planning for the databank size, we were on the right track from the beginning. A size “S+” server from IBM with a 256 GB main memory should meet our requirements.
The running-time analysis showed that currently we must reckon with a downtime of one to two days, i.e. from Friday night at 11 pm until roughly Tuesday morning at 8 am. We will probably get it done faster, but we do not want to take any risks. Outside of the invoice periods and the monthly closing statement we can do without our system as a service provider for two days.
Nonetheless we are considering a repetition of Wave 0, in order to achieve an optimal running-time with the help of the SAP DMO (Database Migration Option). The SAP DMO, part of the SAP SUM (Software Update Manager) carries out upgrade and migration in one step. We will make the decision next week.
Since the work logic of the databank has been altered with SAP HANA, we must run tests to find out the extent to which our ABAP adaptations support the new «thinking». Otherwise, our own reports und transactions would not reach the performance enhancement through SAP HANA, and thus faster reporting would continue to be unattainable. We have tested our ABAP Code with the so-called SAP Code Inspector. This involves a «check report» from SAP with which one can analyze ABAP Code with a view toward—among other things— HANA-compatibility. We allowed the Code Inspector to run for all of our in-house developments. Important: it cannot be started until we have migrated to HANA. Thus one does not know in advance what to expect. After the first run-through we were amazed: the zealous Inspector had actually racked up more than 1000 «hits». A brief exchange with SAP on the subject resulted in the installation of an update, which also updated the Code Inspector. Thereafter we were left with only 57 hits. We reckon with an average time expenditure of two hours per hit. This estimate is based on the experiences of our Solution Factory during the very first tests with SAP HANA.
Soon I will write about the beginning of Phase 1. If you have questions before then, just write me a comment. I will be happy to respond.