A comparative statement shows at once any radical departure from normal conditions and accepted standards, and is, in reality, the manager's barometer of factory operating. The discovery that his operating expenses are increasing without a corresponding increase in the output, means that the storm signals are immediately raised, and there are likely to be squalls ahead in the department responsible for the increase, with an explanation in order from its foreman. The operating statement, then, should show up excessive operating expense, what it is, where it is, and what caused it. =33. Source of Data Used.= Having now in mind what characteristics should be embodied in the tabulation, proceed to gather the necessary data for the statements. Continue the original plan and make the _Operating Expense Statement_ consistent with the _Percentage Method_, and extract the data for same from the cost records and books of account in a factory where this method is used. =34. Expense Manufacturing Departments.= First prepare the shop operating expense statement for the manufacturing departments. If the cost records have been kept in two binders──one for operating expense in _Expense Ledger No. 1_, and the other for production in _Production Ledger No. 2_──the procedure is simple. The _Private Ledger_ account for each department shows the total expense for each month posted in total, with all the details shown in _Expense Ledger No. 1_, to which now refer. Inasmuch as everything is charged to some job number, both labor and material, it is simply a matter of drawing off the job totals, which will check the department total expense as shown in the _Private Ledger_. A convenient grouping of job numbers will be found of great assistance; say _Jobs 1─99. Standing expense orders._ _100─999. Special expense orders._ Generally, _Job 1_ is used to cover miscellaneous expense costs not covered by other job numbers, and includes _foremen_, _sub─foremen_, _clerks_, _tool─room men_, _helpers_, _watchman_, _small repairs_, etc., both labor and material. In the matter of repairs, it will be noted that such charges originate from two different sources: those done by the department for itself, and those done for the department by another department, and frequently spoken of as _inter─department_ work. By providing two cost─sheets for labor items on _Job 1_, one for direct labor charges, and the other for inter─department labor, the two items may be easily kept separate. The material on _Job 1_ should also be kept in the same manner. The reason for this is apparent, as it shows up at once how much a foreman is charging to his department himself, and how much is being charged to him by other foremen on inter─department work.