本文利用統計方法推導出在不同的信賴水準、樣本數n及預期製程能力水準之下,製程能力弱度指標C/sub pp/的最大臨界值,並透過該臨界值訂出一個檢定程序,以判斷製程是否合乎能力水準。同時利用Zar(l978)和Wilson- Hilferty(1931)所分別提出常態分配的近似式,推導出樣本數n以達到製程指標信賴界限的規格水準。 In this paper we find the maximal critical values under some givenconfidence levels, sample size and expected process capabilities, andthen construct a testing procedure to make a decision on whether thegiven process meets the capability requirement. Furthermore, theformulae of approximated sample size n are derived by usingapproximated formulae of normal distribution proposed by Zar (1978)and Wilson - Hilferty (1931), respectively.