CONTROL-SYSTEM QUALITY IS FREE

The phrase ''Quality is Free'' has been bantered about since 1980 when P.H. Crosby wrote the book of that title. Quality experts say that th e title should have been ''Quality is Free for Those Willing to Invest Upfront''. The point is well taken. Costs include those incurred thro ughout the life of the project. This point is emphasized by the qualit y requirements of ISO 9000, an international series of standards on qu ality management and quality assurance. A ''life cycle cost evaluation '' can show how to minimize overall costs. This life cycle cost is an important part of the general ''quality loop'' described in ISO 9004 ( 1987). Many factors including design costs, purchase costs, installati on costs, start-up costs, energy costs, repair costs, and costs of shu tdown must be included. A full reliability evaluation of the system is necessary to feed the model.