Too Many Zeroes

Hi ZH,

see articles on G-control Chart (search Main page)

Other option is: define 2 CTQ's.

CTQ1= % of non-zero's over longer time period; and treat it as you would reject level (no USL, LB=T=0)
CTQ2= count (or %) if >0 over the time/amount already chosen and analyse this as reject level.
Both together give an indication of quality. Danger is in analysing CTQ2 over time because of gaps in time axis (each time there was a 0 in your original data).

Remi