Requisites

Abstract

All artifacts of mankind will eventually fail in service or be discarded because of wear or obsolescence. This was as true for the roads and aquaducts of Rome as it is today for the infrastructure of America. All constructs bearing the hallmark of civilization, from the tomahawk to the cruise missle of the same name, suffer from material weakness or imperfection. This applies a fortiori to our electronic systems, computers, and video communication as well as the military’s smart-bombs and the Concorde’s avionics. Palliative efforts include preventative maintenance for machines and medicines for humankind. But always “an ounce of prevention is better than a pound of cure” and not only because it is earlier and cheaper. The origins of ubiquitious failure are manifold; the designer has neglected or been unaware of the severity of some of the factors of the invironment in which the system/structure must operate; the owner-operator of the system has needfully operated it outside its design envelope; the manufacturer failed to eliminate minor defects from the system either during construction or inspection; the supplier has substituted inferior material, causing inherent weaknesses in a component. Such imperfections can cause the early and unexpected failure of the system, or just the incapability of the system to perform its function during its warranteed life. Such practice may lead to hazards both to the operators and to the public weal.