This study proposes a new approach combining the chemical reaction optimization framework with the uni- fied tabu search (UTS) heuristic to solve the capacitated vehicle routing problem (CVRP). The CVRP is one of the most well-studied problems not only because of its real-life applications but also due to the fact that the CVRP could be used to evaluate the efficiency of new algorithms and opti- mization methods. Chemical reaction optimization (CRO)
is a new optimization framework mimicking the nature of chemical reactions. The CRO method has proved to be very effective for solving NP-hard optimization problems such as the quadratic assignment problem, neural network training, the knapsack problem, and the traveling salesman problem.
We also present the design of elementary chemical reac- tion operations, the adaptation of the UTS algorithm to educate solutions in these operations. Finally, a thorough testing against well-known benchmark problems has been conducted. Experimental results show that the proposed algo- rithm is efficient and highly competitive in comparison with several prominent algorithms for this problem. The presented methodology may be a fine approach for developing similar algorithms to address other routing variants.