Editorial for the special issue on experimental design for reliability and life testingThe design of experiments (DOE) is a cornerstone of quality and reliability engineering. It provides structured methodologies for planning, conducting, and analyzing experiments to ensure that the data obtained is both accurate and informative. In reliability engineering, where the goal is often to predict and improve the lifespan and performance of components and systems, robust reliability testing is essential. It allows researchers to systematically explore the effects of various factors on system reliability, identify optimal conditions, and develop models that can predict failures and inform maintenance strategies. The importance of DOE in reliability research cannot be overstated. This special issue on experimental design and reliability consists of ten papers that exemplify the forefront of research and innovation in reliability engineering. These papers highlight the critical role that experimental design plays in advancing the field, providing novel methodologies, optimization techniques, and practical applications that enhance the reliability and safety of engineering systems.Bayesian methods and experimental design play a pivotal role in reliability engineering, as demonstrated by the studies of Taylor et al. 1 and Wang et al. 2 Both papers highlight the robustness of Bayesian methods in handling complex reliability issues. The former paper develops Bayesian D-optimal designs for life testing with censoring. This approach provides a robust framework for improving the efficiency and accuracy of life testing experiments. The latter paper, which applies Bayesian analysis to reliability improvement experiments with nonconstant stresses and heavy censoring, further illustrates the power of Bayesian methods. By optimizing experimental design under varying stress conditions, this study offers valuable insights into improving system reliability.Another theme in this special issue is the development of innovative methodologies for reliability analysis. The paper by Colak and colleagues 3 showcases the integration of artificial neural networks (ANN) with traditional maximum likelihood estimation (MLE) methods to predict the reliability of electrical components. This study demonstrates the potential of ANNs to provide highly accurate reliability predictions, aligning closely with those obtained through MLE. Contrasting this, Wang and colleagues' work 4 on handling missing data in multi-sensor environments offers a novel interpolation method that enhances data integration and system performance. By addressing the critical issue of incomplete data, this methodology ensures more reliable data inputs, which are essential for accurate reliability assessments. Lv and colleagues' framework for robust parameter design and optimization 5 also contributes significantly to this theme. By integrating various optimization techniques, this framework ensures that engineering systems can maintain reliability under diverse conditions.This spec...