Conventional The conventional food service system is the type most establishments havejraditionally used. Foods are purchased for an individual operation in various stages of preparation, but all production is completed and foods are served on the same premises. Following production, foods are held hot or chilled, as appropriate for the menu item, and served as soon as possible  In previous years, conventional food service systems often included a butcher shop, bake shop, and vegetable preparation unit. Currently, many conventional food service operations use pre-portioned meats, baked goods, and canned and frozen vegetables rather than purchasing all types of foods raw and completing processing on premises. Although alternative systems have evolved, the conventional system continues to be the dominant type of food service in the United States. Because of increasing labour costs, managers of conventional food services have gradually made changes in ingredients and menu items purchased in an attempt to reduce the labour needed for meal production. Food procured for conventional systems vary from those with no processing, to those with a limited amount of processing, to those processed completely. Foods with varying degrees of processing are brought into the system and prepared for service in the food production sub-system. As shown in Figure 12.3 some food are merely purchased and held chilled before service, such as milk or butter patties, whereas other menu items are produced in the system from raw foods and held either heated or chilled until time of service. Following receipt and appropriate storage of food items and ingredients, menu items should be prepared as