Measuring Process Capability in a Product Stability

You need to start with identifying the product metrics that characterise performance – these should be your KPIs – yes?

Hi Sandeep, normally you should be first define your busines case to established your project goales and after in conjuction with your BB define which KPI´s are very important to your process. To stability studies depend of the product and the pharmaceutical forms, then you should be analyze and report all specifications results and do tracking to each test. However remember that you need obtain at least 50 individual values or 25 subgroup data to calculate the Cp´s.
Alan
 

I completly agree with Alan that first you need to identify the KPI’s for your process .

Dear Sanddep gupta
Though it is late, i happend to see all replies sent to you by discussions of participants. If you have already got solution, please ignore it other wise you may look into it.
You have some value of the quality characteristic Stability agianst which you would like to assess that of your sample. Here you might be having lower and upper specifications.This is what i could understand it.
For the measure of CPk or CP you need to know the average value and standard deviation. To arrive at these statistics, more no of samples under identical conditions need to to be taken and determine average and standard deviation.Once Cp or Cpk are calculated we can link up with Sigma levels and asses at what levels the process is capable of running defect free production.
If you are already a Six Sigma expert , there may not be any difficulty. If you are only pharmacy pereson, perihaps I amy try to help yopu. Let us know. I do have some experience in drug industry and also about six sigma methodology. Let us know.
k.bhadrayya