Measurement system analysis is crucial in the continuous improvement of manufacturing processes. Gauge Repeatability and Reproducibility (GR&R) is a process of examining the conformity or non-conformity of the major components of a measurement system; tools, equipment, and operators. This reveals the component contributing the most error or variation in the measurement system. This paper reviews GR&R in dimensional measurements with particular emphasis on accuracy, precision and reliability. There is an introduction to metrology and some metrology terminologies to lay the foundation for the appreciation of gauge repeatability and reproducibility. A critical review of some literature on GR&R studies is done and is expanded to cover general dimensional measurement and investigation of two main areas of measurement error in gauges. The effectiveness of a gauge as a measuring tool is crucial in determining the gauge capability thus, this GR&R review.