Stability Study

Shelf Life Estimation

  

The shelf life estimation table shows the specification limits, the confidence level that is used to calculate the shelf life, and the shelf life estimates. If the batch factor is not included in the final model, then the shelf life is the same for all batches. Otherwise, the shelf life for each batch is different, and Minitab displays the shelf life estimate for each batch. The overall shelf life for the product is equal to the smallest of the individual shelf life values.

Example Output

Shelf Life Estimation

 

Lower spec limit = 90

Shelf life = time period in which you can be 95% confident that at least 50% of response is

     above lower spec limit

 

Batch    Shelf Life

1            83.552

2            54.790

3            57.492

4            60.898

5            66.854

Overall      54.790

Interpretation

For the pill data, the final model includes the batch factor, so Minitab displays the shelf life estimates for each batch. The shortest shelf life estimate is 54.79 months, so the overall shelf life for the product is estimated as 54.79 months.