An RFID and Wireless Sensor Network-based Implementation of Workflow Optimization

In this paper we present a radio frequency identification(RFID) and wireless sensor network(WSN)-based implementation of workflow optimization in warehouses. This application belongs to the more general class of supply chain applications including item tracking and tracing, inventory monitoring and control, and asset monitoring and management. We solve the problem of optimally fulfilling an order that involves the retrieval of items that are stored among a large number of shelves scattered throughout a warehouse. The items are RFID-tagged and randomly placed in shelves that have RFID readers which read the RFID tags of individual items and communicate them to a data aggregator or repository. Given a set of items to be retrieved, we utilize an ant-colony based optimization algorithm to calculate the optimal route that a user needs to follow from his/her current location to the various shelves that have the required items. A novel feature of our application is a unified communication framework wherein each RFID reader is considered a node in wireless sensor network (WSN) and the framework facilitates efficient searching and retrieval of the large amounts of real-time data (RFID tags).