The modern milling process is highly mechanised. The tasks of millers include ensuring that the final products meet the required specifications by setting the various milling machines used in the milling process and supervising their operation. The principle of milling is to break open the grain, to separate the bran and endosperm and to grind it to a finished product. At the mill silos, the grain is weighed, quality checked and stored until required for milling. The grain is given a preliminary cleaning and fumigated. The next stage is the cleaning, blending and conditioning of the grain prior too the actual milling process. Cleaning involves the grain passing over various machines to remove all the impurities such as foreign seeds, straw sticks and stones. The different grades of grain are then blended together in order to produce a flour or meal which has the required characteristics of the baking of a good loaf of bread in the case of wheat, or producting a good quality maize meal in the case of maize. The grain is then conditioned by adding water and allowing it to lay over in bins until it has mellowed. The grain in then milled, the process consisting of grinding on a succession of rollermills, and subsequent sieving on various sieving machines, such as a plansifter or purifier. Millers are responsible for all the processes described above and will spend time in each section of the mill during their training period. Once qualified they would have to oversee and ensure the proper function and smooth flow of the plant activities. Other duties would include supervision of staff and safety procedures.