Hi,
Please find answers for your questions.
How to add cost of packing labor in standard cost of 13 digit part number.
Define labour time as one of the activity type in work centre of the packing operation and
maintain the standard values for the same in routing operation. Assign the control key to the operation which is activated with indicator relevant for costing.
Whether key for packing operation need to change for "Relevant to Costing".
Yes
Whether part numbering logic adopted by us is correct or you have better suggestion for part number logic
It depends on the business requirement
Thanks
Kumar