circuit                 package:qcc                 R Documentation

_C_i_r_c_u_i_t _b_o_a_r_d_s _d_a_t_a

_D_e_s_c_r_i_p_t_i_o_n:

     Number of nonconformities observed in 26 successive samples of 100
     printed circuit boards. Sample 6 and 20 are outside the control
     limits. Sample 6 was examined by a new inspector and he did not
     recognize several type of nonconformities that could have been
     present. Furthermore, the unusually large number of
     nonconformities in sample 20 resulted from a temperature control
     problem in the wave soldering machine, which was subsequentely
     repaired. The last 20 samples are further samples collected on
     inspection units (each formed by 100 boards).

_U_s_a_g_e:

     data(circuit)

_F_o_r_m_a_t:

     A data frame with 46 observations on the following 3 variables.

     _x number of defectives in 100 printed circuit boards (inspection
          unit)

     _s_i_z_e sample size

     _t_r_i_a_l trial sample indicator (TRUE/FALSE)

_R_e_f_e_r_e_n_c_e_s:

     Montgomery, D.C. (1991) _Introduction to Statistical Quality
     Control_, 2nd ed, New York, John Wiley & Sons, pp. 173-175

_E_x_a_m_p_l_e_s:

     data(circuit)
     attach(circuit)
     summary(circuit)
     boxplot(x ~ trial)
     plot(x, type="b")
     detach(circuit)

