In their guidance of 2003, the U.S. Department of Health and Human Services, the Food and Drug Administration, the Center for Drug Evaluation and Research (CDER) and the Center for Biologics Evaluation and Research (CBER) describe how to test the stability of drug substances. They suggest testing to demonstrate “how the quality of a drug substance or drug product varies with time under the influence of a variety of environmental factors, such as temperature, humidity, and light”. 
For that, the drug or the drug substance or the drug product is stored under specified conditions and tested, e.g., for a long-term study of over 2 years, every 3 months during the first year, every 6 month during the second year and every year thereafter.
Such studies are very time-consuming.
Kinetics Neo is a NETZSCH software capable of determining the kinetics of a substance decomposition using thermogravimetric measurements. As a final result, it predicts the long-term behavior of the sample at specified temperature and atmosphere conditions, or, in other words, its shelf-life concerning thermal stability.
Kinetics Neo requires only 3 (or more) TGA measurements, so that the sample behavior over a long-time period of 2 years or more can be predicted within some hours.
As an example, the shelf-life prediction of potassium clavulanate is given here.
 Stability Testing of New Drug Substances and Products, U.S. Department of Health and Human Services Food and Drug Administration Center for Drug Evaluation and Research (CDER) Center for Biologics Evaluation and Research (CBER), November 2003, Revision 2, https://www.fda.gov/media/71707/download