The concept of the length-biased distribution is very important in statistics, reliability and survival analysis. In this investigation, a new stochastic order based on the hazard rate of length-biased equilibrium distribution is introduced and studied. Since this new order lies in the framework of the mean residual life and the combination convexity orders, we called it combination mean residual life order. Relationships of this new order with other well-known stochastic orders are given. It was shown that the new order enjoys several reliability properties, which provide some applications in reliability, renewal theory, aging notions and hypothesis testing. As a consequence, on the basis of the combination mean residual life function, a new class of lifetime distributions called decreasing combination mean residual life was proposed and studied. It was shown that the increasing failure rate class is a subclass of the proposed class. Testing exponentiality against this class was addressed and the asymptotic normality of the proposed statistic was established. In addition, the Pitman asymptotic efficacy, the power and the critical values of the proposed statistic were calculated. Further properties and applications of the new order and the proposed class can be considered in the future of this research. In particular, preservation properties of the new order under convolution and formation of coherent structure are interesting topics, and they still remain as open problems.