Dynamic Genetic Algorithm for Search in Web Service Compositions Based on Global QoS Evaluations

A dynamic genetic algorithm characterized by a dynamic evolution evaluation policy is presented to select optimal web service composite plans from a lot of composite plans on the basis of global Quality-of-Service (QoS) constraints. In this genetic algorithm, a dynamic fitness evaluation policy is proposed on the basis of a relation matrix coding scheme of genome. The fitness evaluation policy includes a dynamic penalty technology. It can get more excellent composite service plan because it accords with the characteristic of Web service selection very well. The simulation results on Web service selection with global QoS constraints have shown that the improved genetic algorithm can gain effectively the composite service plan that satisfies the global QoS requirements.