In recent years, it has been made possible to compose exiting services when a user's request cannot be satisfied by a single web service. Web service composition is faced with several challenges among which is the rapid growth in the number of available web services leading to increased number of web services offering the same functionalities. The difference between similar services is Quality of Service (QoS) consisting of various non-functional factors such as execution time, availability, security, etc. As a result, multiple choices are possible in making a composition plan. Among numerous plans, selecting a composition plan that fulfills customer's requirements has become an important and time-consuming problem. In this paper, the researchers propose a semi-heuristic genetic algorithm that is a combination of both a heuristic method and the genetic algorithm. This heuristic method changes chromosomes based on unsatisfied constraints. Research findings show that the proposed method can be applied to find a composition plan that satisfies user's requirements more efficiently than other methods.
A QoS-oriented Web service composition approach based on multi-population genetic algorithm for Internet of things