Overall Equipment Effectiveness (OEE) is a powerful metric of manufacturing performance incorporating measures of the utilisation, yield and efficiency of a given process, machine or manufacturing line. When associated with the reasons for performance loss, OEE provides the means to compare and prioritise improvement efforts. This research assesses the current systems used in the high-volume production lines of Company-X, a precision manufacturer of computer components. This assessment led to the design of a singular methodology that functions in a high-volume production environment, in the rapid prototyping production, and the program qualification production divisions of Company-X. The methodology defined indicators (Utilisation, Efficiency and Yield), and factors that must be recorded on an individual piece of equipment within a manufacturing line to determine its OEE. These equipment-level records were captured utilising the equipment’s computer-controller, supplemented by minimal user input, to minimise the non-value added activities associated with data-entry. The methodology also determined the means to aggregate the records to prioritize improvement activities (Weighted OEE Pareto) and calculate the manufacturing lines overall performance (Overall Line Effectiveness).