This document describes research using an artificial neural network (ANN) and graphical user interface (GUI) to estimate fabrication time for rig construction projects. The ANN was trained on data from 960 completed fabrication jobs. It used 3 input parameters (height, plate thickness, inspection criteria) to predict fabrication time in days. Eleven different ANN architectures were tested, with a 3-50-1 network achieving the best results. A GUI was developed to allow users to simulate the best ANN model without ANN expertise and obtain fabrication time estimates. The research demonstrated the potential of ANNs for construction time forecasting when extensive historical data is available.