This, however, has changed. Software now brakes automobiles, flies airplanes, controls railroads, and manages financial transactions. Daily, software moves over one trillion dollars in the world's financial markets. Defective software is increasingly expensive, and it can even be dangerous. In the threatening world of terrorists and hackers, software defects increase our exposure.
Software is now the critical component in many products.
It is cheaper to use microprocessor chips and software than even simple hardware logic. My Army friends tell me that the trigger mechanisms in advanced side arms fire the guns through software. Artillery shells now have several thousand bytes of code and new military radios are microprocessors with antennae. Once their defects are found, software-based systems are more reliable than hardware. In the nuclear power industry, for example, electro-mechanical instruments are being replaced by computerized controls.