Data Migration for Open Purchase Order

Question

Hi, All,
Is there anyone know how to Count the volume for Open Purchase Order. What's the normal strategy for the Data Migration and Cut-over stage?
My client want to know how many Open Purchase Order in the legacy system and then determine manual or automatic data migration. If manual, how to do? If automatic, how to do? Because all materials and vendors, plants are different number. How to track? How to find out to match between new and old?
Thank you very much

Answer 1

JC,
Sounds a bit early to be making decisions about the realization phase.  It doesn't sound like you have finished the Blueprinting phase yet, much less the testing phase.
Anyhow, in my experience I typically use LSMW (Legacy system migration workbench) to load MM master data (material masters), Inventory (WIP, RM, FG, etc) Purchasing Master data (Vendors, Purchase Info Records, Source Lists, Quota Arrangements), and Purchasing transactional documents (POs, PurReqs, Scheduling Agreements, etc).  Depending on the complexity and volume of data, it  may be necessary to write custom programs to load the data.  You will find this out during your requirements gathering.
It is uncommon but possible to load all of these data manually.  I have never run across a client that wants to pay a consultant's hourly rate to sit at a terminal to peck away loading master data, so if the client intends to have his own users enter the data manually, the project manager should make provision that there will be qualified TRAINED client employees available for this data entry.  I did help with a portion of a conversion once manually; of Sales Credits, but there were only about 30 SD docs to load.   I did this the evening before go-live day, while I was waiting for some of my LSMW projects to complete in the background.
A good opportunity to 'practice' your data loads is right after you have completed your development and customization, and you have gotten the approval from the client to proceed from the pilot build to the full test environment.  Once you have moved your workbench and customization into the client's test environment, but before integration testing, you can mass load all, or a substantial portion of your conversion data into the qual system.  You can treat it like a dry run for go-live, and fine tune your processes, as well as your LSMW projects.
Yes, it is good practice to generate comparisons between legacy and SAP even if the client doesn't ask for it. For Purchase orders on the SAP side, you could use any of the standard SAP Purchasing reports, such as ME2W, ME2M, ME2C, ME2L, ME2N.  If these reports do not meet the requirements of the client, you could write a query to display the loaded data, or have an ABAPer write a custom report.
You didn't ask, but you should also do comparisons of ALL loaded data - including master data.
It sounds like you are implying that the client wants YOU to extract the legacy data.  For an SAP consultant, this is not very realistic (unless the legacy system is another SAP system).  Most of us do not understand the workings of the myriad legacy systems.  The client is usually expected to produce one or more legacy system technical experts for you to liase with.  You normally negotiate with the technical expert about every facet of of the data migration.  In addition, you will liase with business users, who will help you and the implementation team to logically validate that the final solution (turnkey SAP production system, fully loaded with data) will meet the client's business needs.
Finally, you mentioned how do you track the mapping of master data between legacy and SAP.  There are many ways to do this.  I normally try to get the legacy person do the conversion on his end, eg, when he gives you the load file, you would like to have already translated the master data and inserted the SAP relevant values into the file.  If this is not possible, I usually use MS Access databases to maintain a master map, and I perform the mapping on a PC.  If your data package is small, you can probably get by using MS Excel or similar.
Good Luck,
DB49