Data conversion in SAP project - conversion from legacy system to SAP ECC.
I would like to share my experience in data conversion process with the SAP community. Data conversion is one of the most critical processes in successful SAP implementation projects. This process is a part of the realization step in the "ASAP" methodology (step 1 : project preparation. step 2: blueprint. step 3: realization. Step 4: final preparation. Step 5: go live). SAP advisors and local implementers are usually responsible to carry out data conversion from legacy system to the SAP ECC. I have also heard of SAP projects in which the Basis team has carried out this process.
The data converted is used only in order to set up master data in ECC . it is not used to set up historical transactional data from legacy system.
there are different tools which convert data: 1. SAP ECC built in tool via LSMW transaction code. 2. External tool named Process runner which communicates easily with ECC. I used Process runner which was purchased by my company.
Two of the most important qualities which are required in order to succeed in this process are : 1. Thoroughness 2. Communicating & understanding your Customer needs.
As mentioned above, data conversion process is part of the realization step.The realization step begins after the advisors (or local implementers) have finished writing down and submitting the blueprint documents for customer's approval. After the approval, the implementers start to customize and writing down specification documents for new developments in the Development area in ECC. Only then, its possible to start the data conversion process.
There are sub steps in data conversions:
1. Mapping the necessary fields in the ECC object that will be filled with data (I.E: Equipment object in PM module)
Here you need to be well aware of what is written in blueprint documents regarding your SAP objects.
It's recommended to differentiate between value obligatory fields of this object and value non obligatory fields. Some times object classification is needed. This happens when object regular fields are not enough to store entire data from legacy system. I used classification in equipment object that represented electric generators.
2. Creating one instance master data manually
The purpose of this step is to verify that the implementer is able to create master data manually before conducting the recording.
3. Recording master data set up via Process Runner (or LSMW).
In case the recording is not accurate, or changes in setting up the master data are need to be done after recording, the recording has to start all over again. Thus it is important for you to be certain how to set up the objects master data correctly.In case the recording was accurate and you saved it, Process runner creates an EXCEL file with proper columns to be filled (according to the fields you have entered in the recording) in order to set up several instances automatically.
For example : You have recorded setting up master data of one piece of equipment with certain data. After you have saved the recording, Process runner will create the proper structure in EXCEL for future recording. Then, you will be able to fill the EXCEL file proper columns with as much pieces of equipment data as needed, and execute the recording again when you wish to set up those pieces. In this way, multiple pieces of equipment will be created via Process Runner.
4. Creating Extraction program to extract data from legacy system
In this step you need to specify to the legacy system administrator (he is usually a MF programmer) in accurate manner which fields, and what tables you need the data from. Second thing you need to consider: what is the data population to be extracted (I.E: only active pieces of equipment / data which was created after certain date. your customer will know the answers to this question ). The system administrator should then prepare the program in the legacy system for future use. In my project, the legacy system was MF system which was written in ADABAS NATURAL. I sent specification documents to the administrator specifying fields to extract and what data population to extract.
If there is necessity to do some kind of data manipulation (I.E : 1. Equipment type in legacy contains values: A , B , C while ECC equipment type was customized to contain values AA , BB , CC respectively 2. changing format of date values etc.. ), the administrator has to code it in the program.
It's very advisable that this program sorts the output columns identically to the columns order in the EXCEL file from previous step. The administrator should sort the columns in the right way. Eventually, the extraction program creates EXCEL file full of extraction data which fits the EXCEL file structure and format from previous step.
5. Analyzing errors log file and fixing extraction program
In this step the EXCEL file is full of data to be loaded to SAP ECC. try loading 50 percent of all rows in the file. Process runner will create output results. If there are any mistakes while the program is trying to create master data, It will indicate the reasons for it.You should analyze and fix the program respectively.
6. Preparing deletion and archiving program in SAP ECC
Eventually there is a chance you will need to delete any of the data that was loaded due to any reason. So first, you will need to distinguish the data that was converted and loaded to SAP ECC area from other data that was created manually by users. the best way to do it is using SAP standard report and specifying in the selection screen of the report the SAP user that created the data. For example in my project a certain programmer was using Process runner to load the data. The entire data he loaded was created under his user code. Thus, it was easy to distinguish the data. After the report extracted that data, mark what ever is necessary for deletion and use SARA tcode to Archive the data (I will post separately specific guide how to archive data in SAP using SARA tcode).
Hope this information will help you working with SAP. For any question regarding this process fill free to ask me.