A new Four-Stage Activity-Based Costing (4ABC) model and computer system were developed to allocate costs more accurately. The model uses different levels of activity cost drivers to assign costs from resources to products. This helps estimate how much cost each product absorbs based on its activities. The 4ABC model can track both indirect and direct costs equally, unlike traditional systems. Time-based cost drivers were also considered for better accuracy. The model provides detailed cost information, including total and unit costs, direct and indirect costs, and profitability analysis. The computer-based system simplifies the cost allocation process.