@ O. Peter following

Hi Zulfa,

Here is a similar article which might be of some use to you.

The Application of Six Sigma in Process Control of Raw Water Quality on Pharmaceutical Industry at Indonesia

Dino Rimantho1 , Dedi Hernadi2 , Bambang Cahyadi3 , Rini Prasetyani4 & Yani Kurniawan5

https://www.ripublication.com/ijaer17/ijaerv12n6_07.pdf

Regards

Martin

Dear Zulfa Wahida

As I understand this question the sigma referred to here is the standard deviation of the bell shaped probability curve, such that at a 1 sigma probability (that is about 95 times out of 100) the required water quality has been achieved. At the six sigma level of water quality, the successful pass rate is expected to be something like 99.99966 % and you are ‘claiming’ that out of tolerance water is very unlikely (probability 100 -99.99966%) to interfere with production.

Refer this Link:

Article A novel approach to lean six sigma project management: a con...

It is a case of improve the process that need DMAIC (Define-Measure-Analyse-Improve-Control) it is the best problem solving method than others.

Important steps are:-

voice of the customer (Internal >> Employee) referred to International standard of safety (( ISO 45001 focuses on identifying and controlling risks rather than hazards, as is currently required in OHSAS 18001 )).

MSA & sample: To ensure that device , person have no wrong errors during measuring the water samples regarding biological & chemical components.

Root cause analysis to detect defects

pilot test (re-sampling)

5 S technuqie

Metrology (by engineer)

Control chart to detect any variation.

** Best software : Minitab version 18 until now.