Using Duty Cycles in System Reliability Analysis
Components of a system may not operate continuously during a systems mission, or may be subjected to loads greater or lesser than the rated loads during system operation. To model this, a factor called the "duty cycle" is used. The duty cycle can also be used to account for changes in environmental stress, such as temperature changes, that may affect the operation of a component. The use of duty cycles in reliability modeling, especially in system reliability modeling and analysis, provides additional flexibility for the analyst. This article explains how to perform analysis using duty cycles in BlockSim 7.

Introduction to the Generalized Eyring Life-Stress Relationship
When analyzing accelerated test data obtained from tests that involve multiple stress types, it is often assumed that the different stresses are independent and do not interact. The Hot Topics article in Issue 53 of Reliability HotWire described a methodology for analyzing the significance of interactions among different stress types. This article presents a life-stress relationship that is often used to analyze data obtained when temperature and a second non-thermal stress (e.g. voltage) are the accelerated stresses of a test and their interaction is also of interest. This relationship, called the generalized Eyring relationship, is available in ALTA 7 PRO.