a quick guide to successfully migrating data as part of an acquisition or sap upgrade
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A Quick Guide to Successfully Migrating Data as Part of an Acquisition or SAP UpgradeTRANSCRIPT
SCM Expert - A Quick Guide to Successfully Migrating Data as Part of an Acquisition or SAP Upgrade
http://www.scmexpertonline.com/article.cfm?id=5779[17/04/2011 1:20:37]
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Data Management, Implementations, Upgrades, and Migrations, Inventory management, Master Data,Procurement
A Quick Guide to Successfully Migrating Data as Partof an Acquisition or SAP Upgrade
by Yogesh Lohiya, Senior SAP MM Consultant, Infosys Technologies, Ltd. • April 8, 2011
Using SAP ERP procurement and inventory functions as examples, learn the steps behind a typical
data migration process.
Key Concept
A data migration strategy is one of the biggest and most crucial hurdles to clear in any acquisitionor SAP upgrade project. This strategy involves four data-related steps: extraction, transformation,loading, and reconciliation. A properly planned and executed data migration strategy paves a strongfoundation for the success of your project; however, if you fail to follow a data migration strategycorrectly, it could lead to project failure.
Data migration to an SAP system can occur if an SAP-run company acquires a non-SAP shop, a businessrunning SAP performs an upgrade to a latest SAP version, or an entirely new implementation occurs.Irrespective of whether it is a fresh implementation project, rollout, or merger, the desired results are thesame: efficient and smooth transformation of master and transactional data to or within the SAP system.
With proper integration and coordination with business stakeholders, a well-managed data migrationprocess can produce significant business gains across the enterprise. However, poorly-managed migrationprocesses will likely result in significant time and cost overruns and lack of integrity in the converteddata. Therefore, it is important to understand the complete end-to-end migration process and make surethat there is a data migration plan in place that integrates smoothly with the overall project plan.
Let me take you through all the steps involved in a typical data migration process with examples of datamigration objects for SAP ERP procurement and inventory. This article is useful for anyone working on anSAP project involving data migration, be it a conversion lead, project manager, or functional consultant ifyour company hires one. I have used the methodology explained in this article in four successful datamigration projects.
Figure 1 explains the complete data migration process in simple terms. It shows the four major steps ina typical data migration process:
1. Extraction of data from the source system, including data cleansing
2. Transformation and subsequent validation of data
3. Loading data into the SAP system
4. Reconciliation of data
Every step helps achieve efficient results. Let’s go through the details of each step below.
Figure 1 The major steps behind data migration
A Quick Guide to Successfully Migrating Data as Partof an Acquisition or SAP Upgrade
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SCM Expert - A Quick Guide to Successfully Migrating Data as Part of an Acquisition or SAP Upgrade
http://www.scmexpertonline.com/article.cfm?id=5779[17/04/2011 1:20:37]
Extract Your Data
The first thing you need to do in a data migration project is understand the legacy system and itslandscape (i.e., whether it has separate development, quality, and production environments). Then it’simportant to study the source data thoroughly to understand its content, structure, quality, and integrity.Decide what data to move and how much data to move. Prepare a list of master and transactional datathat needs to migrate — consider data for material master/bill of materials, customer master, vendormaster, inventory, G/L accounts, cost center, fixed assets, and purchasing. Identify stakeholders whoprovide data for testing of migration objects and for final loading into your SAP system.
Once you define what data needs to migrate, the next step is to extract that data from the sourcesystem. You can accomplish this in many ways, but choosing which method to use largely depends onthe source system’s technical complexity, budget, resources, and volume of data.
Below are examples of how one can initiate the extraction process:
Business provides the data in the form of files such as Microsoft Excel or tab-delimited text. This isthe best method if the volume is not large and if lots of technical work is necessary to connect tothe source legacy system.
Develop a program that automatically fetches data from the source system’s database tables andstores it in Excel files. This method is good if the technical team has access to the source systemand data is available in the form of relational database tables (e.g., Oracle SQL table).
Use standard tools, such SAP BusinessObjects Data Integrator, to connect to a legacy system toextract legacy data.
It is the responsibility of a conversion analyst to ensure that each and every SAP field involved with theproject is explained to business users so that they can relate source data fields with SAP table fields. Thiswill improve the quality of data coming from the source system. For example, a typical initial inventoryupload in an SAP system requires an input file with the following fields:
Material (MATNR) — This field is meant for all the active materials with stock quantities greaterthan zero.
Plant (WERKS) and storage location (SLOC) — Business needs to provide these values if stock isstored at a plant/SLOC level in the legacy system.
Batch (CHARG) — If materials are managed at batch level, business needs to provide batchnumbers associated with each material.
Quantity (ERFMG) — This field is meant for the quantity of material to be migrated.
Vendor (LIFNRS) — If materials are managed at a subcontractor level — such as material providedto vendor (MPV) — or as consignment stock, then business needs to provide vendor numbers atwhich stock is available. Here, it is important for the conversion project team member to explainthat if stock is MPV, then they might not need to provide SLOC above because stock will becaptured in the system as subcontracting stock.
Special stock indicator (SOBKZ) and movement type (BWART) — A conversion team member canpopulate these fields after getting information from the business depending on what type of stockdata is provided. For example, if it is MPV subcontracting stock, then the standard movement typein SAP is 561 for taking initial stock into the SAP system. The special stock indicator is the letter Ofor subcontracting stock. For plant stock at storage location level, it is going to be 561 and thespecial stock indicator is left blank because it needs to be loaded under a plant and storagelocation.
Cleanse the Source Data
This step ensures that the data you upload into your SAP system is of the utmost quality. Here, theresponsibility of a conversion team member is to define rules after discussion with business about whatdata needs consideration. For example, with purchase order data, a rule could be only to consider openpurchase orders created in the last year. Cleansing data rules result from a mutual agreement betweenbusiness and the conversion project team. Table 1 shows an example of a cleansing tracking sheet.
SCM Expert - A Quick Guide to Successfully Migrating Data as Part of an Acquisition or SAP Upgrade
http://www.scmexpertonline.com/article.cfm?id=5779[17/04/2011 1:20:37]
Table 1 Data clean-up tracking sheet
Transform Data Among Sources
In this step, you perform mapping between source data fields and SAP fields by either using automatedtools — such as the Legacy System Migration Workbench (LSMW) — for high volume and complex data,or manually for low volume and simple data. The following are options to perform this step:
Manually using formulas in Excel. This is fastest way to handle transformation if data volumes arelow and there are few fields that require transformation. For example, in the initial stock uploadfile in Table 2, assume only the plant number is being changed and other values will becreated/configured as they are in the SAP system (e.g., legacy plant FRTT has been renamed asCP01 in the SAP system, but other fields will not undergo any changes). Then you only need totransform the plant data, and that can be done easily in Excel using the VLOOKUP function.
Table 2 Initial stock upload file
If technical team support is available, use SQL tables to perform the transformation. In thismethod, a technical team builds a SQL table with all the required fields, creates mapping tableswith old and new values, and writes a stored procedure to transform the old values (source fields)to new values (SAP fields). This method is suitable if you have a large number of fields thatrequire transformation. However, if technical team support is not available, then it is better tostick with SAP standard LSMW.
Use SAP BusinessObjects Data Integrator, a standard tool that has reusable and sharabletransforms and functions (drag and drop) that minimize hard coding.
Validate Transformed Data
In this step, business confirms that data has been transformed correctly, which is an important step for adata conversion project. Here, you provide a comparison between a source data file provided by businessand the transformed data. This preload validation step can be done using Excel sheet macros or througha SQL table. The final report should have all the required fields with old and new value columns showingcompared results. For example, Table 3 shows Plant and SLOC comparisons (just two columns of thecomplete file are shown). Here, I have used EXACT function in Excel.
SCM Expert - A Quick Guide to Successfully Migrating Data as Part of an Acquisition or SAP Upgrade
http://www.scmexpertonline.com/article.cfm?id=5779[17/04/2011 1:20:37]
Table 3 Comparison columns for data validation
In a compare column you want to see a FALSE value if a field required a transformation because FALSEmeans the old value has changed to a new value. If you see TRUE in a comparison column, that meansan old value has not been transformed and you need to investigate why it did not convert. In Table 3,Row 5, the values for Old plant and Old SLOC did not convert to New plant and New SLOC values. In sucha case, business should go through the preload validation report thoroughly and provide confirmation tothe project team that all the data has been transformed correctly. Only at that point should the projectteam move ahead with the next step of loading data into the SAP system.
Load Data Into the SAP System
Once business signs off on the preload validation report, you are ready to load your data into the SAPsystem. It is important to identify the data loading technique at the initial stage of the project because itmight take time to develop loading programs if you are not using standard loading techniques. SAPprovides LSMW for migration of data, and it comes as an add-on with your SAP installation. If usedproperly, LSMW can save time and money by avoiding development of complex loading programs, whichin turn reduces your dependency on an ABAP or technical team. This is a win-win situation for thefunctional and technical teams, as the technical team can focus on critical objects in the project and thefunctional team can perform the migration steps independently from beginning to end without anytechnical help.
There are four ways to upload data into the SAP system using LSMW:
Standard batch/direct input
Batch input recording
Business object method (i.e., BAPI)
Intermediate Document (IDoc)
Note
For more details about LSMW, see the SCM Expert article, “Reduce Your Reliance on ABAP for LogisticsData Conversion Using LSMW,” by Mitresh Kundalia.
It is advisable to first check if loading can be done using a BAPI or IDoc because they are the fastest andmost efficient methods, so verify that you have a standard BAPI defined in the system for your object.Examples of LSMW BAPIs and IDocs for purchasing documents are given in Figures 2, 3, and 4. You cansee these screens by using transaction LSMW.
Figure 2 BAPI and IDoc for purchase order upload
SCM Expert - A Quick Guide to Successfully Migrating Data as Part of an Acquisition or SAP Upgrade
http://www.scmexpertonline.com/article.cfm?id=5779[17/04/2011 1:20:37]
Figure 3 BAPI and IDoc for scheduling agreement upload
Figure 4 BAPI and IDoc for contract upload
Once you complete all the steps of LSMW, you can check the status of loading by choosing Create IDOCOverview in LSMW via transaction LSMW (Figure 5).
Figure 5 Select Create IDoc Overview
If loading was successful, you see the Current status of IDoc designated as 53; however, if loading failed,you see the Current status as 51. Figure 6 shows a successful loading with the Current status as 53.
SCM Expert - A Quick Guide to Successfully Migrating Data as Part of an Acquisition or SAP Upgrade
http://www.scmexpertonline.com/article.cfm?id=5779[17/04/2011 1:20:37]
Figure 6 Successful loading report
Create a Reconciliation Report
Once your data has been loaded successfully into the SAP system, the final step is to generate areconciliation report, which compares transformed data and loaded data in the SAP system. This reportensures that the loading program has worked properly and all the transformed data has been uploadedinto SAP correctly. Like the previous pre-load validation report, here, you can also use SQL queries orExcel to compare transformed and uploaded data.
For example, in the case of inventory data migration, you already have the transformed data comparisons(Table 3). To get the uploaded data file you have to go to an SAP table for storage location data formaterial (MARD). To access this table, use transaction SE16, enter the table name as MARD, enter yourplant number, and press F8. This gives you the entire inventory data loaded into SAP at plant and storagelocation level. Similarly for subcontracting stock you have to use a table for special stocks for vendors(MSLB).
Once you get the data, you have to save it into an Excel file. Do this via menu option System > List >Save > Local File, give a name to the file using an extension of .xls, and save it on your desktop (Figure7).
Figure 7 Save your data to a local file
Now you have two Excel files: one having transformed data and another having uploaded data from theSAP system. You need to combine both files into a single version so that you can use Excel’s EXACTfunction to compare transformed and loaded data. Here, for all the fields you should get a TRUE value,which means transformed data is loaded as it is in the SAP system (Table 3). If you get a FALSE value inany cell, it implies data has not been loaded correctly and you need to investigate why the loadingprogram did not load the value correctly. Note the difference in whether a TRUE is tye desirable valuebetween Tables 3 and 4.
SCM Expert - A Quick Guide to Successfully Migrating Data as Part of an Acquisition or SAP Upgrade
http://www.scmexpertonline.com/article.cfm?id=5779[17/04/2011 1:20:37]
Table 4 Transformed data has loaded correctly into the SAP system
Once the project team ensures that the reconciliation report is giving the desired results, the team seekssign-off from the business that all the data has been loaded correctly.
I have followed the above migration strategy during four projects and all went go-live successfullywithout a single issue. However, apart from following the strategy correctly, it is important that theproject manager make a proper project plan to accommodate the data migration strategy as one of themajor milestones. Another important aspect I always follow is to start working on the data migrationstrategy at the beginning of the project instead of waiting for the design to freeze. This gives you theopportunity to understand the data in detail, which in turn helps you create a foolproof data migrationstrategy.
Yogesh Lohiya is working as a senior SAP MM consultant in a large data migration project for a Fortune500 client. He has more than eight years of consulting experience, and has worked on various SAP globalrollouts and data migration projects in the materials management area. You may reach him by email [email protected].
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