The economic importance of wheat and its contribution to the diets of humans and livestock cannot be disputed. Wheat is grown in most parts of the world, from near-arctic to near-equatorial latitudes. It is the most important crop among the cereals by area planted and is followed in importance by corn, barley and sorghum. The amount of wheat traded internationally exceeds that of all other grains. Furthermore, the protein and caloric content of wheat is greater than that of any other food crop. Most wheat is consumed in the form of baked goods, mainly bread; therefore, wheat grains must be milled to produce flour prior to consumption. Wheat is also used as an ingredient in compound feedstuffs, starch production and as a feed stock in ethanol production. The wheat flour is produced during the mechanized process at the factory. Therefore, increasing the productivity of this mechanized process is most important. The maintenance unit is one of the best opportunities to increase productivity of a mechanized system. For many systems, the category of human resources is considered to be the most important system capital, which has a significant impact on system performance. Since, The manpower productivity of the Shoale flour factory during the last ten years was evaluated taking into account the reliability of the system. The results indicated that the winnower and mill of flour factory included ??.??% and ??.??% of total failures, respectively. The results indicated that the spiral (??.?%), feeder (??.?%) and elevator (??.?%) caused the majority of recorded failures in winnower parts. Furthermore, the roller mill (??.?%), spiral (??.?%) and sieve (?.?%) parts of mill were more prone to failure than the rest. The manpower efficiency and factory equipment failure rate showed a positive relationship as well as there is a positive relationship between the manpower effectiveness and the factory equipment reliability.