To ensure that your results are valid, consider the following guidelines when you collect data.
- The data should include a 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.
- The response variable should be continuous
- If the response variable is categorical, your model is less likely to meet the assumptions of the analysis, to accurately describe your data, or to make useful predictions.
- Collect data using best practices
To ensure that your results are valid, consider the following guidelines:
- Make certain that the data represent the population of interest.
- Collect enough data to provide the necessary precision.
- Measure variables as accurately and precisely as possible.
- Record the data in the order it is collected.