Advances on the Stress Interaction Model

In a reliability experiment, a combination of temperature cycling (TC) and temperature humidity bias (THB) stress was applied. The outcome varied significantly with the sequence of the stress tests. It made a difference whether first TC-stress was performed and then THB-stress, or the other way round. A statistical model is created for this effect. It is called the Stress Interaction Model. The stress sequence is given as a path in BBR². The hazard function is set up as a vector field. Unless the hazard function is a potential of a vector field, the path integral depends on the way from point A to point B. In this setup, the sequence of the applied stress tests, say the stress history, is reflected in the reliability function. In this paper, the Stress Interaction Model is extended by a shape factor.