Abstract: The quality control charts are one of the most important tools in controlling statistical quality. It is a cost added to the product. There are many different control charts, the most widely used are the variable control charts. These charts depend on the size of the sample. The larger the sample size the greater the accuracy and cost. The cost increases when destructive testing is implemented. The aim of the research is to propose a methodology to benefit from previous data, to improve accuracy and reduce costs. The methodology has been applied for a 25 samples, each of them a 5 sized sample. The average was calculated based on samples of different sizes (2-5), its average values are considered as the single sample applied in (I-MR) chart. The calculations and the control chart drawing were performed by the Software "Minitab". This research also studied the process capability results that were obtained by the proposed methodology as well as their indicators. The number of trails to achieve the accredited control limits for the succeeding application for characteristic understudy was reduced. The value of standard deviation decreases when the sample size increases. The process capability, also, increased with the increase in the size of the sample. The calculated mean process shifted from the target mean towards its USL for all sample sizes under study. The proposed methodology shows that the switch to (I-MR) chart is easy and can be easily applied by the workers. It is necessary to state the values of the last sample, from which the control limits were found which is considered to be the previous sample which calculates the moving average of the first sample of the application.