product hierarchy
An organizational chart type of array of the products offered in a given market, breaking first into product class, then product form, then variations on form, then brand. For the transportation market, the top layer is broken into cars, trucks, buses, etc. The second layer breaks cars by form (sedans, station wagons, convertibles), trucks by form (semi, heavy duty, pick-up), etc. The third layer breaks each of these class/form groupings one more time, for example showing automobile sedans as two-door, four-door, etc. The fourth layer breaks each of these smaller groups into brands (Ford, Chevrolet, etc.). There are various options within these product hierarchy dimensions, so that the array can be designed to fit the needs of the analyst. The hierarchy concept fits services as well as it does goods.