An activity-based costing system that is designed for internal decision-making will not conform to generally accepted accounting principles because Multiple Choice under activity-based costing some manufacturing costs (i.e., the costs of idle capacity and organization-sustaining costs) will not be assigned to products under activity-based costing the sum of all product costs does not equal the total costs of the company. activity-based costing has not been approved by the United Nation's International Accounting Board activity-based costing results in less accurate costs than more traditional costing methods based on direct labor- hours or machine-hours