Student
133 Points
Joined July 2013
Suspense account doesn't belong to the real, nominal or personal category as such. At the time of preparation of Trial Balance if any unknown difference is found between the credit and debit sides, the amount is transfered to the Suspense account until the reason for difference is found out. It is a temperory/dummy account which facilitates quick preparation of financial statements.
And to the second question, Operating Costing, I guess? You will have to be a little more specific. Lots of techniques of costing can be applied here.