Let be a connected graph representing a distribution network with k items. The elements of represent demand centers, while contains the suppliers. Every node can supply the items. To each node is associated a weight , which represents its installation cost. Every node requires the items. Each item claims a delivery time at most . A weight is associated with every arc , which denotes the needed time to reach node y directly from node x. In this paper a method is developed which detects a subset in order to minimize the total delivery time under a given budget restriction.
