I used this small program while doing telephone billing system conversions. It is quick and easy to create and it has short term and long term value.
I ask the customer for a screen shot of their most important information from their current system. This example is the subscriber file. It takes me no more than a couple hours to create a pretty good replica of their old Subscriber details.
First I print all the field description info onto the screen. Right after that is being displayed I put a DUMMY input statement. I save that screen capture to a newcust0001.bmp BitMap file. Then I comment out the dummy input statement and put in a display of the newly created newcust0001.bmp Now I can put the subscriber detail up on the screen with simple prints.
With this quick program I can examine the new data in the same format as the client and by holding down the enter-key see it flash through all the conversion records. After the conversion and the old system is gone. The new clients like to be able to refer back to the old system to compare accounts old and new.
Being this was so easy to do. I'd ask for WorkOrder and transaction info from the old system so that they could be referenced as well. We never convert that data but it is important. What was the last work order on the account and check the transactions to see payments etc. Sort of ETL without the "Load". Just the ET.
So there you go. Source code to the Bestest and 2nd Bestest programs ever. Just use the bestest and maybe peek at the code to see how bad it is and with 2nd Bestest. Use it and use it lots. Years ago (early 70's) a good friend of mine said if he was designing systems they would all be text files. With this combo of 2 bestestes. It makes good sense. Very good sense.