Scale up is generally defined as the process of increasing batch size. In process scale up a formula is transformed into a viable, robust product by the development of a reliable and practical method of manufacturing that effect the orderly transition from laboratory to routine processing in a full-scale production facility. It must include a close examination of the formula to determine its ability to withstand batch-scale and process modification. So process scale up of Metformin HCL tablet includes Trial Batches, Exhibit Batches and Validation Batch. After these batches produce large scale up Metformin HCL Tablets. During the scale up process controls are evaluated, valuated and finalized in addition, appropriate records and report are issued to support good manufacturing practices and to provide the historical development of the production, formulation, process equipments train, and specification.