A novel system for continuously monitoring the position of individual products and resources in 3D space is currently being developed. Continuous position monitoring will permit misplaced products to be found, leading to significant productivity improvements by reducing the costs associated with lost products. The positioning system under development locates products and items by locating an electronic tag placed on each item, permitting the tracking of up to 1000 products in any one factory at any time. Presented is the architecture of the prototype system being developed as well as a synopsis of the problems encountered and the solutions that have been found. Proof-of-concept results are presented including the accuracy to which the relative arrival times can be measured using two estimation techniques and the relationship between these arrival times, the placement of the receivers and the final positional accuracy. The proof-of-concept tests and accompanying analysis demonstrate that sub-meter position location accuracy is possible in the factory.