In the textile and apparel manufacturing industry, there are four main process plants namely spinning, weaving, wet-processing/finishing, and garments. The spinning plant consists of several sections, from blow room to winding including a ring frame. viii In Bahir Dar Textile Share Company, there are two yarn manufacturing lines which are rotor spinning and ring spinning lines. In the yarn manufacturing process industry, the production process requires the non-stop operation of the automatic production line equipment. A stoppage in a production line, due to a bottleneck and failure of the equipment, causes an inefficient or drop in the production rate and quality problems on the products. Since the productivity of ring frame line is lowered, the thesis was conducted on a ring frame yarn manufacturing process line in a spinning department where 21 & 40 Ne carded yarns were produced for the local and export market. Data were collected from the ring frame spinning process line including carding, drawing frame, roving, and ring frame spinning processes of planned production and working time, and downtimes based on major stoppage losses. The OEE of all the machines of each workstation except roving process is very low comparatively from world class OEE value (85%) of manufacturing machines. Mainly ring frame machines showed OEE of 38.6%. The amount of waiting time in roving process is 174 minute for 1400 minute working time. This roving process work station has the highest waiting time in the whole flow. Other stations are not facing any queue as much as the roving. All this information indicates that roving workstation is the process bottleneck which has to be minimized to attain the aim of this thesis. The bottleneck is happened because of imbalance feeding or single roving machine can’t feed effectively to five ring frame machines. This leads to bottleneck workstation. After adding the new machine to the existing line and giving necessary input regarding that the output stands to 1371 kg in 1400 minutes. Regarding this result, the waiting time has decreased for that individual workstation from 174 minute to 0.00 minute or 100% which has come to a label with others.