APPARATUS AND METHOD FOR EVALUATING OPERABILITY OF APPLIANCES AND AN APPARATUS FOR IMPROVING THE OPERABILITY OF THE APPLIANCES

A method for evaluating operability of a completed appliance at a designing stage includes the steps of forming a function-operation correspondence table which includes functions that the completed appliance is supposed to have, operational parts to exert each of the functions, and a number of times each of the operational parts is actuated to exert each of the functions; finding a total number of times each of the operational parts is actuated to exert all the functions in a case where all the functions are selected one time each, by using the function-operation correspondence table; adding up all the total numbers of times; calculating a ratio of the number of times each of the operational parts is actuated to the total numbers of times all the operational parts are actuated to exert all the functions; finding unbalance of using frequencies among the operational parts, from the calculated ratio and the number of the operational parts; and evaluating the operability of the appliance, based on the unbalance found.