HI Raja sekaran,
What is the formula you used in Work center for the activity Labour? standard or customized? whether its relevant for costing? Whether the mentioned operation is relevant for costing? Have you maintained the activity cost for the specific period (month/year)? Whether your activity cost value is too low like .0056(example)? System will consider only 2 decimal point only for cost. Please check the all above and let us know
Thanks