Sir if we have received critical complaint like glass piece found inside of the bottle. (that bottle was plastic but glass found) so what will be probable reason for the same.
Hello! In addition, or alongside, with any quality tool for root cause analysis (for example, Ishikawa), I suggest conducting a 3 level investigation based on possible sources of particle contamination.
First level - Inherent particles.
See if this type of particles could come from, or be generated from, the product itself or its packaging materials. Since you’re dealing with plastic bottles, I assume there is no glassware related to product container nor packagin materials.
Second level - Intrinsic particles.
See possible sources of glass-type contamination from within the process; these could be generated from processing equipment, product or material handling, or if that mfg line is shared/used with any glass materilas that could have not been removed previously (perhaps that same line manufactures plastic and glass bottles).
Third level- Extrinsic particles
These are the most difficult to identify since they are not related to the product or its mfg process. These particles are introduced from outside of the mfg process, for example: glass particles carried into from clothing, dust, materials previously contaminated and not effectively cleaned, etc.
Depending on the most probable source (inherent, intrinsic or extrinsic) you can establish process controls more effectively.
I hope this can help you identify the root cause of your glass contamination more effectively.