Software Safety and Liability Prevention
Lewis Bass, Esquire, P.E. - Attorney & Safety Engineer - Law Offices of Lewis Bass (SSA Journal - September 1989 pp. 70 - 75 )

This paper examines the liability of manufacturers of software controlled semiconductor process equipment and the liability faced by individuals who develop such software. These equipment manufacturers and software developers have exposure to lawsuits arising from system failures caused by software deficiencies. The paper begins with an overview of various legal theories of responsibility. Presented are ways in which a software developer and equipment manufacturer can minimize, to the greatest extent possible, liabilities associated with the use of software and semiconductor process equipment controlled by software. The use and reliance on computer software in the semiconductor and medical industry, and in our daily lives, has increased dramatically in the last several decades. This proliferation of computer equipment, along with our increased acceptance of new systems, have combined in the potential exposure of more people than ever to hazards associated with software system failures. Since 1986, three cases of physical injury have been reported from a computer software error in a medical device, the Theracâ„¢ 25 linear accelerator, which is intended to provide radiation therapy to cancer patients. One patient became paralyzed, another lost the use of her arm, and a third died as a result of overexposure to the radiation. Another example of harm from a software-related error is the sinking of the British ship H.M.S. Sheffield in its action to retake the Falkland Islands from Argentina. The Sheffield defense system failed to detect an Argentine-launched Exocet missile. The software designers had programmed the system to recognize the Exocet missile as friendly since it was in the British arsenal. However, designers failed to consider the possibility that a foe may also have this missile, with tragic consequences. Our dependence on software, its increasing sophistication and the mounting level of risk it poses from all types of products require the application of software system safety techniques. At the same time, those exposed to the potential of a software failure, whether the terms of lost production time, lost wages or serious personal injury, are becoming more demanding of software developers and equipment manufacturers. They stress not only efficiency and user-friendliness, but also system safety. These considerations pose an increasing burden for both the software programmer and equipment manufacturer. A failure to meet these demands, to the satisfaction of both their customers and the courts, poses legal exposure which may jeopardize their ability to remain in business.