Abstract
A simple procedure for evaluating the symbolic reliability of a complex system in presented. The switching (Boolean) functions of system success and system failure are expressed as the intersections of complements to the prime implicants of these functions. Shannon's expansion about suitable keystone variables is repeatedly applied to either or both functions until subexpressions with statistically independent terms are obtained. The procedure applies to a variety of reliability problems. In addition, it is relatively fast and yields simple symbolic expressions.