A Dynamic Web Service Composition Algorithm Based on TOPSIS
Longchang Zhang, Hua Zou, Fangchun Yang · Journal of Networks · 2011
Abstract—Multi-period QoS evaluations have to be considered for obtaining a reliable decision in the service selection process. Besides, open and dynamic Internet environment increased the uncertainty of decision-making. To solve the above difficulties, this paper presents a novel hybrid data type (including real numbers, interval numbers, triangular fuzzy numbers and intuitionistic fuzzy numbers) QoS model, multi-period hybrid QoS aggregating operator and a strategy for aggregating composition service QoS firstly. Furthermore, a dynamic Web service composition algorithm based on TOPSIS (DWSCA_TOPSIS) is presented to evaluate multi-period hybrid QoS data. DWSCA_TOPSIS includes four main steps: converting hybrid QoS into intervals, calculating weighted normalized decision-matrix, determining the positive-ideal and negative-ideal solution, calculating the close-degrees of candidates. Finally, some experiments are given using actual QoS data to demonstrate the benefits and effectiveness of our approach. Index Terms—Web service, service composition, quality of service (QoS), TOPSIS, multi-period hybrid QoS, multiattribute decision-making I.