Keeping the process in control while minimizing costs

Hints:

1. Run without making any interventions first (without having labor substitutions or having equipment recalibrations) and see how the total costs will change.

2. Make interventions (recalibration of equipment and/or make a laor substitution). See how the total costs will reduce. Understand the implications of both activities:

(a) Recalibration of equipment will reset the process mean to its original value; thus, recalibrating equipment when there is an assignable variation on X-bar chart

(b) Making a labor substitution will reset the process variance to its original value; thus, make a labor substitution when there is an assignable variation on the R-chart.

You can do both when there are assignable variations on X-bar and R charts.