Because the fixed assets categories share a common information system, the types of transactions and the types and levels of risks are similar, and they share similar controls, and error in one of the disaggregated portions is indicative of an error in another disagrregated portion. As such, the engagement team has determined the disaggregated portions are similar. The acceptable difference for each disaggregated portion will be a proportionate allocation of the acceptable difference at the significant account level for depreciation expense.