This research is aimed at increasing efficiency of cash distribution from three distributioncenters delivered to 377 branches, and 3,699 automatic teller machines by using Cluster First –Route Second technique. New concept of assignment problem with time window is presented inthis paper for clustering. A Group Sweep Algorithm, which is modified from a traditional SweepAlgorithm combined with a nearest neighbor search, is also presented as the routingmethodology. Application software has developed using PHP and MySQL. AMPL with CPLEX10.0 is used to solve the assignment problem and is perfectly embraced underneath thedeveloped application software to allow the user-friendly experience. The software allow theflexibility in changing various parameters such as, capacity proportion of each cash distributioncenter, speed of vehicle, service time at each branch or ATM, time window of each branch orATM or distribution center, etc. The result shows that 11 vehicle can be reduced resulting incost reduction in a total amount of US$195,097 annually.