(4) Economy
Economy is the measure to see the level of the cost of materials used for the evaluation method, labor hours for preparation, personnel and time for evaluation, etc. Low cost makes implementation easy, but generally superior evaluation methods involve higher cost.
If the cost is at the level that enables prompt implementation, there is no need to change the evaluation method. If the cost is too high to implement, there is a need to change the method. The decision is difficult when the method is feasible but the cost is considerably high. In such a case, a decision is made considering the balance with other functions.