Computer system usage is booming-the market is increasing, and microprocessors are entering areas such as industrial process control and transportation. The signs of another great expansion are all around us. For example, the global minicomputer market is growing from $310 million annual sales in
1971 to $2 billion in 1976 to an estimated $6.5 billion in 1981.1
However, despite all the computer usage to date,
the efforts of many highly-motivated people and organizations, and the vast outpouring of the software engineering field, the common computer systems with which we come into daily contact continue to fail. A few close-to-home examples make the point: