Economic design of Hotelling’s T2 control chart on the presence of fixed sampling rate and exponentially assignable causes


School of Industrial Engineering, Islamic Azad University, South Tehran Branch, Tehran, Iran


Control charts are extensively used in manufacturing
contexts to monitor production processes. This
article illustrates economical design of a variable sample
size and control limit Hotelling’s T2 control chart based on
a novel cost model when occurrence times of the assignable
causes are exponentially distributed. The proposed
nonlinear cost model is an extension of Duncan’s (J Am
Stat Assoc 51: 228–242, 1956) model which was employed
for univariate cases. Applying genetic algorithm to find
optimum parameter values and using an L33 orthogonal
array in sensitivity analysis on the model parameters is
investigated through a numerical example to illustrate the
effectiveness of the proposed approach.