An actlivity$-$based costing system that is designed for Internal decision$-$makIng will not conform to generally accepted accounting principles because:

activity$-$based costing results in less accurate costs than more traditional costing methods based on direct labor$-$hours or machine$-$hours.

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.

under activity$-$based costing some manufacturing costs $($i$.$e$.,$ the costs of idle capacity and organization$-$sustaining costs$)$ will not be assigned to products.