6. Process or Product Monitoring and Control
6.5. Tutorials
6.5.4. Elements of Multivariate Analysis
6.5.4.3. Hotelling's T squared

## Chart for Individual Observations -- Phase II

Control limits In Phase II, each value of $$Q_j$$ would be plotted against the UCL of $$\frac{p(m+1)(m-1)}{m^2 - mp} F_{\alpha,\, (p, \, m-p)} \, ,$$ with, as before, $$p$$ denoting the number of characteristics.
Further Information The control limit expressions given in this section and the immediately preceding sections are given in Ryan (2000, Chapter 9).