The number of defects can be actually tracked statistically to ascertain whether the total number of defects is within a particular range.

For example, if it’s the quality check of a flat then Quality Control professionals know the range of defects that are to be expected in a typical flat. Let us assume that the typical range is between 30 to 40 defects. If the QC team finds that the number of defects is 70 or 80 in the Control Chart, it means that the situation is alarming and warrants an intervention. So the defects figures going awry is a useful indication to the Quality Control teams that they need to identify what is going wrong on site. Only quantifying the defects is one aspect but putting the range of defect is also required to reach the issues.

Control Charts is a statistical method by which you can account for the variability on site and you get a standard range.

Now, once that standard band is identified, everything that is beyond that band needs to be analyzed and questioned. Quality Control managers need to look at various aspects that could be causing such issues.