Use to analyze the stability of a product over time and to determine the product's shelf life. Minitab fits a linear model to represent the relationship between the response variable, the time variable, and an optional batch factor. The batch factor can be fixed or random. Based on the model, Minitab calculates the shelf life, which is the length of time that the response is expected to remain within the specifications.

You want to determine the shelf life for pills that contain a new drug. The concentration of the drug in the pills decreases over time. You want to determine when the pills reach 90% of the intended concentration.

You create 5 batches of the medication and test one pill from each batch at 9 different times.

Data: ShelfLife.MTW (available in the Sample Data folder).