Although the need for new systems (instead of constant maintenance of older systems) is often quite apparent to the MIS department, their advantages are not so readily realized by senior management –which sees only costs and risks instead of benefits. As a result, MIS managers must prove the costs and benefits of such projects. This column examines the difficulty of measuring the costs and benefits of four generations of systems –batch, online, DBMS based, and maintenance motivated – and explains why MIS managers should not only rewrite old systems but turn their attention toward the development of new and innovative systems.