Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2009.79.87GhoseiriK. F. GhannadpourS. 1200991This study aims to solve Vehicle Routing Problem with Time Windows (VRPTW), which has received considerable attention in recent years, using hybrid genetic algorithm. Vehicle Routing Problem with Time Windows is an extension of the well-known Vehicle Routing Problem (VRP) and involves a fleet of vehicles set-off from a depot to serve a number of customers at different geographic locations with various demands within specific time windows before returning to the depot eventually. To solve this problem, this study suggests a hybrid genetic algorithm combined with Push Forward Insertion Heuristic (PFIH) to make an initial solution and λ-interchange mechanism to neighborhood search and improving method. The proposed genetic algorithm uses an integer representation in which a string of customer identifiers represents the sequence of deliveries covered by each of the vehicles. Part of initial population is initialized using Push Forward Insertion Heuristic (PFIH) and part is initialized randomly. A λ-interchange mechanism interchanges the customers between routes and generates neighborhood solution. At the end, in order to prove the validity of the suggested model, fourteen instances of Solomon`s 56 benchmark problems-selected randomly- are solved and compared with the other meta-heuristic methods. The results indicate the good quality of the method.]]>Achutan, N., L. Caccettal and S. Hill,200337153169Alvarenga G.B., G.R. Mateus and G. de Tomi,20073415611584Berger, J. and M. Barkaoui,20032003pp: 646656Braysy, O. and M. Gendreau,200539119139Braysy, O. and M. Gendreau,200210211237Blanton, J.L., Jr. and R.L. Wainwright,19931993pp: 452459Cerda, J. and R. Dondo,200717614781507Petch, R.J. and S. Salhi,20031336992Correa, E.S., M.T.A. Steiner, A.A. Freitas and C. Carnieri,20012001pp: 12681275Crevier, B., J.F. Cordeau and G. Laporte,2007176756773Czech, Z.J. and P. Czarnas,20022002pp: 376383De Backer B., V. Furnon, P. Shaw, P. Kilby and P. Prosser,20006501523Gambardella, L.M., E.D. Taillard and G. Agazzi,19991999pp: 63-76pp: 63-76Holland, J.H.,19922nd Edn.,Irnich, S., B. Funke and T. Grunert,20063324052429Kim, B.I., S. Kim and S. Sahoo,20063336243642Laporte, G. and F. Semet,20011st Edn.,pp: 109-128pp: 109-128Li, F., B. Golden and E. Wasil,20053211651179Ombuki, B., B.J. Ross and F. Hanshar,2006241730Pisinger, D. and S. Ropke,20053424032435Rochat, Y. and E.D. Taillard,19951147167Shaw, P.,19981998pp: 417431Solomon, M.M.,198735254265Tan, K.C., L.H. Lee, K.Q. Zhu and K. Qu,200115281295Tan, K.C., Y.H. Chew and L.H. Lee,200634115151Tan, K.C., C.Y. Cheong and C.K. Goh,2007177813839Thangiah, S.R.,19991999pp: 347-381pp: 347-381Wren, A.,19711st Edn.,