Re: Specification Limits - When a product does not meet the specification limits
Thank you all for the concerns to this topic!
let me expain my problems.
To conduct the capability analysis (assume the process output is stable and normally distributed), we have to know the USL or LSL. I didn't observe the process of data collection. I only have the final data report sheet. On that sheet, it said that standard value of this product is greater than 3.5. (i.e. min = 3.5) and the target value is 4.59. That is, a nonconformity will be considered if any value of this product is less than 3.5.
I am thinking about two approaches for the specification limits.
One is that the LSL should be 3.5, and NO USL.
The other is to use the UCL and LCL as the USL and LSL, respectively.
I tried both approaches in minitab, and it is obvious that the results are dramatically different.
My question is which approach is the right way to set up the specification limit.
Please let me know if there is any better method. Thanks again!