Executing Impact Analysis

Downtime-optimized conversion saves technical downtime, but introduces additional complexity to the maintenance. To understand potential impacts of the procedure that are relevant in uptime (migration, data conversion). SAP offers the Impact Analysis delivered with Software Update Manager Toolbox. Software Update Manager Toolbox is a collection of tools related to Software Update Manager delivered separately using the transportable correction instruction (TCI) note.

Impact Analysis is one of the tools. It analyzes impact in technical and business perspective. For analysis, Impact Analysis requires two sets of information: Usage statistics data from production system and table classification information of Software Update Manager. Table classification is a phase of Software Update Manager in which every table in the system gets a classification assigned, defining how the table will be handled during the maintenance process. The classification determines for example if a table needs to be cloned or access will be restricted to read-only access for a specific phase.

This means, to execute Impact Analysis, at least one conversion run with Database Migration Option (DMO) (or at least the classification phase) needs to be finished to obtain classification data. As mentioned, the analysis is based on statistical data retrieved from the productive system, as user activity is happening in that system. For export of data, a tool is available in Software Update Manager Toolbox. This means, Software Update Manager Toolbox has to be available in all systems, in which downtime-optimized conversion is used. For retrieval of production statistics, it needs to be available in production at the beginning of the project.

The impact analysis is an important step in the preparation of the downtime-optimized procedure. It reports the following categories of impact:

• Read-only restrictions for end users for specific tables on productive instance (only relevant for customizing, anyhow no changes on production expected).
• Some database triggers might have to be removed (none as of SUM 2.0 SP 21).
• Additional database space requirements due to table cloning.
• Additional daily database growth due to change recording.

The Impact Analysis is executed by Software Update Manager once during a downtime-optimized conversion run. However, is can (and should) also be run manually in Software Update Manager Toolbox.

Software Update Manager Toolbox delivers following tools relevant for downtime-optimized conversion:

• Export of SUM classification data: exports table classification data from a system on which Software Update Manager already finished classification.
• Uptime Table Selection for downtime-optimized DMO: Selection of tables that will be migrated during uptime in a downtime-optimized Database Migration Option (DMO) run or downtime-optimized conversion run.
• Impact Analysis: Manual execution of Impact Analysis.
• Export Table Statistics for Impact Analysis: exports statistical usage data (should be executed on production system).

To retrieve statistics from production (PRD), open Software Update Manager Toolbox (transaction STBX) on the productive system and select tool Export of SUM classification data. Select a period and export the data. The default file name is ZDIMPANA.ZIP. In any system in which Software Update Manager Toolbox is present, tool Impact Analysis can be used. In the example below, it is a sandbox (SBX) system, on which the conversion is already finished. Here the ZDIMPANA.ZIP file containing the production statistics are uploaded. Optionally, Software Update Manager table classification data can be uploaded, if the Impact Analysis is executed on a system on which Software Update Manager did not yet run.

To execute the analysis, you use the Impact Analysis tool. The tool not only requires the impact analysis statistics from production (file ZDIMPANA.ZIP), but also the table classification results (file PUTTBSHD.ZIP). The table classification file is taken from the existing system (assuming that a conversion run was finished on that system), or you can export this file and import it on a separate system.

In the following example, Impact Analysis has been executed in Software Update Manager Toolbox. Statistics file ZDIMPANA.ZIP was uploaded manually, the table classification data was taken from the local system. Header data summarizes the scenario, system and the transport status of the statistics file.

The overall summary shows all findings of Impact Analysis, regardless of their relevance according to the statistics from production. In this example, twelve tables will have restricted access, that is, will be read-only, however the findings at the bottom indicate, that only one table is critical and two others might be critical. In the last section, the Impact Analysis findings are summarized. At the bottom, details on the findings can be found - for example, which tables become read-only or for which tables a high change recording is expected. There are certain thresholds that define whether severity is high or warning.

As activity on production may differ between months or weeks, it es recommended to execute Impact Analysis with different sets of statistical data. The periods should match the expected time frame for conversion on production system to determine the impact as closely as possible. Please note that Impact Analysis does not replace testing activities.

In the following exercise, you will learn execute the Impact Analysis in Software Update Manager Toolbox.