Stability Studies and Estimating Shelf Life

Steven Wachs

Steven Wachs has 25 years of wide-ranging industry experience in both technical and management positions. Steve has worked as a statistician at Ford Motor Company where he has extensive experience in the development of statistical models, reliability analysis, designed experimentation, and statistical process control. Read more...

Manufacturers of foods, drugs, consumer goods, and other products must determine the shelf life of their products so that customers know when the product can be expected to perform as intended. Many approaches are available to quantify the "shelf life" and the method(s) chosen often depend on the testing time available.

This virtual boot camp discusses the steps to design a stability study and analyze the results to estimate a product's shelf life. This 3-hour session will discuss the use of regression models to model the relationship between the response variable(s) and time, as well as cover models useful for describing non-linear degradation over time. You will also learn about methods for handling non-normal response data and the use of accelerating variables to shorten the study time and the models required. Additionally, approaches for including the effect of other variables on shelf life (such as packaging type, storage conditions) will be discussed with several examples and case studies to illustrate the methods.

At the end of the session, you’ll come away with various useful techniques and methods to conduct the analysis of resulting data and stability study to estimating shelf life while focusing on the interpretation and communication of results. You will get straightforward and easy-to-understand instructions to immediately apply these learning to your work.

Participants will be given the opportunity to conduct a stability study using Minitab software. Data files will be provided ahead of the boot camp if you choose to follow along with the speaker while he explains how to use the software. You can also register for a 30-day trial of Minitab at

Session 1
  • Planning a Stability Study (Study Objectives, Identifying Resources)
  • Determining Performance Specifications
  • Defining Shelf Life
  • Confidence Levels
  • Importance of Adequate Measurement Systems
Session 2
  • Linear Regression Modeling
  • Non-linear Regression Modeling
  • Methods for Handing Non-Normal Response Data
  • Introduction to Accelerated Stability Testing
Session 3
  • Accelerated Stress Factors and Models
  • Sample Size Implications and Guidelines
  • Modeling Shelf Life as a function of other predictors (packaging type, storage conditions, etc.)
  • R&D Personnel
  • Product Development Personnel
  • Quality Personnel
  • Lab Testing Personnel
  • Operations / Production Managers
  • Quality Assurance Managers, Engineers
  • Process or Manufacturing Engineers or Managers
  • Program or Product Managers
  • Antibiotic QC Supervisor