Assume that this is present in a copy book and due to some changes ws-part2 has changed to X(7). for this change only program B had recompiled.
so in program A the ws-part2 declaration is numeric and in program B it is Alphanumeric.
while calling the program B no data is present in the ws-part2 and in program B the ws-part2 is loaded with some Alphanumeric data like 'ABCD123'. once the control is back to programA, whether it give any abends or process normally since the ws-part2 declaration is numeric and it holding the Alpha numeric data.
Please clarify whether it give any abends or process normal.
This type of topic has been discussed many times in this forum, if you try to search the Cobol forum for NUMERIC, you should find a number of topics with answers for your question. If you still don't understand, ask again.