however, software carries its own reliability risks. reliance on a software program to trigger an alarm assumes that the analog signal, the programmer's logic code and hmi, the plc or pc running the programs, and the interaction between all of the above, are all entirely trustworthy. this is exacerbated by frequently changing computer hardware & firmware platforms and the need to modify existing software. alternatively new annunciator panels are utilizing long lasting and bright leds that significantly reduce the cost and maintenance of the panels. these new versions of the traditional system are still preferred over computer based systems especially in critical plants like nuclear power generation, oil and gas.