Reliability of a system with m-stresses and n-strengths

In certain situations many stresses and strengths may act on a system. It is observed that if more than one stress act on a single strength system then the reliability of the system is same as the reliability of the single stress strength components in series system when stress and strength follow exponential distribution. It is also observed that if more than one strength act on a single stress system then the reliability of the system is same as the reliability of the single stress strength components in parallel system when stress and strength follow exponential distribution. There may be a chance that m-stresses act on a n-strengths system. It is observed by the computations that the reliability of the system is approximately equivalent to the average of the reliability of series-parallel and parallel-series system when stress and strength follow exponential distribution. And also observed that if stress parameter mu(i) increases then the reliability of the system increases. If strength parameter lambda(j) increases then the reliability of the system decreases. Here mu(i) and lambda(j) are the reciprocal to the means of the stress and strength respectively.