GINQUAL, a digital simulation model, predicts cotton quality and quantity parameters as stripper harvested cotton is processed through different sequences of gin processing equipment. The model currently simulates cotton processing through various combinations of an airline cleaner, dryer, incline cleaner, stick machine, bur machine, combination bur and stick machine, extractor-feeder-cleaner, the ginstand, and multiple passes through lint cleaners. The model can accommodate different processing rates, variable moisture contents and different operating parameters. The simulation model tracks cotton quality, quantity and moisture content as it passes through each machine in the processing system and predicts grade as a function of foreign matter content and color levels of the lint.