Stratified Sample provides great precision, in service industry most of the accounts has various process with different tolerance and way of working.
Stratified sampling is most commonly used for quality check processes, below mentioned are a few key advantages:
1. Assures representation of all groups/queue in sample population selected.
2. Characteristics of each layer can be estimated and comparisons can be driven for the same.
3. Reduces Variability from systematic approach
Thanks
Rahul Choudhary.