This paper is designed a VSI X-CRL synthetic control chart in aspect of economy. We found the optimal sampling interval and various control limit factors under various cost parameters using cost function, proposed Lorenzen and Vance. Optimal design parame

This paper presents a economic design of synthetic control chart that is an VSI(variable samlping interval) X control chart and conforming run length chart. Computer simulation is carried out for comparing performance of developed control chart with X-CRM synthetic chart. We found that optimal parameter of suggested chart for minimize quality cost. And then a comparison and analysis between synthetic VSI X-CRL chart and X-CRM synthetic chart in the economic aspect. Then VSI X-CRL chart consistently produces smaller quality cost than X-CRM synthetic chart.