We have 5-6 WIP Jobs , where overhead variances are generated

OH variances are generated for the job.

The job is started and closed during Oct-23 and the particular Item does not have the OH cost element in the Standard cost history during the period Oct-23, the amount is appearing 0.00$. It has the OH cost only from Dec-23 . We are unable to understand how the system is calculating OH incurred amount for the particular Job. OH Relived is 0.00$ which is resulting in OH variance for the job.

Any pointers on the same will be really helpful ,Thanks in advance!!