This paper presents a discrete bat algorithm to solve the vehicle routing problem with time window (VRPTW). The proposed algorithm defines position

velocity

updated operation of the position

updated operation of the velocity and updated operation of the frequency

and uses a method which combines the penal function with vectorial comparison to deal with constrained conditions. The proposed algorithm adopts random inserted strategy

inserted research strategy for the vehicle with minimum customers

ordinary inserted research strategy

exchanged research strategy and 2-Opt strategy with time window to expand the search space and enhance the convergent rate. Experimental results show that

the proposed algorithm has a stronger optimization capability

higher robustness and less time consumption

key parameter values and strategies used in this paper can improve performances of the proposed algorithm

and according to the hypotheses testing

there exsits a significant difference between the proposed algorithm and comparative algorithms.