The research investigates current strategies that help automobile manufacturers to enhance their productivity. The study utilizes robust statistical methods to define the most important factors on the Hours per Vehicle (HPV) in the automotive industry in North American manufacturing plants. Data are synthesized using a uniform methodology from information supplied by the plants from 1999-2007. Overall, there are 682 manufacturing plants in the statistical sample from ten automobile manufacturers brands. During the study period, the HPV was reduced 51.84 minutes on average in each year.

During a comprehensive literature review, thirteen important factors that affect HPV were defined. Annual production volume, flexible manufacturing, and year factors improve HPV. However, vehicle variety, model types, annual working days, and launching a new model impact the HPV negatively. On average, the HPV is lower for Japanese and joint ventures in comparison to American automotive manufacturers by 1.92 and 1.86 hours, respectively. Launching a new model and adding a new variety in body styles or chassis configurations raises the HPV up to 2.9 and 0.38 hours, respectively, depending on the vehicle class. The HPV regression equations that are provided in this research may be used effectively to help automotive manufacturers to set guidelines to improve their productivity.