Quality of Service Multicast routing has been classified as an NP-Complete problem. As a consequence, multiple bio-inspired models have been implemented to solve it. Before implementing the bio-inspired models is necessary to select and encoding system. It denotes the way of representing the problem such that the bio-inspired models understand it and can be used to solve it. In this work we present a review of multiple encoding systems. Then, we select an encoding system, describe it and carry out a performance analysis of the k-shortest path algorithms implemented in the selected encoding system. Finally, we present the best algorithm found by the simulations to be implemented in the encoding approach for a QoS multicast routing algorithm.