I want to know about ,how the Swift message are genearted.
To my understanding, based on the copybook layout test data file is genearted and application programs are used to map the test data file to the swift layout and genearte the swift messages.
Even if I could follow all that you were saying, the answer would be - for Production, no, nothing to do with test data.
You have some SWIFT record layouts. You have some rules. You follow the rules, populating the appropriate SWIFT records with the appropriate values and "write" them. There will be technical stuff specific to your site as to what exactly "write" means in your case.