Composite materials are predominant in spacecraft structures. In order to define layers´ thicknesses and fiber orientations, structural composite analyses under quasi-static, sine vibration and thermo-elastic loading needs to be conducted. Here, composite strength reserves can be evaluated in a correct manner. For acoustic environment and random vibration the analyses methods are different. There is no commercial approach available accurately determining composite strength reserves under random loading. Existing approximate and conservative approaches to estimate the strength ratios use quasi-static equivalent loads, which are only applicable for trivial structural behavior. This generally leads to inaccurate and unreliable strength analyses for complex structures. However, the probability distributions of the composite failure indices in a random load environment can be calculated exactly enabling a proper reliability analysis, as shown in the initial academic work of Segalman et al. [1], Pitoiset et al. [2], Fuente et al. [3] and Thelemann et al. [4]. Within this paper, the authors present, that the probabilistic approach is applicable in an industrial context and superior to existing approaches. As a consequence, the quality of the engineering analysis is improved, enabling a faster and optimized development of lightweight CFRP structures under random loading. Thus, the development costs can be reduced and mass savings of the structure can be achieved. References [1] Segalman, D., Reese , G., Field, , R., Jr. , and Fulcher , C. "Estimating the Probability Distribution of von Mises Stress for Structures Undergoing Random Excitation." ASME. J. Vib. Acoust. January 2000; 122(1): 42–48. https://doi.org/10.1115/1.568442. [2] Pitoiset, X.; Preumont, A.; Kernilis, A., Tools for a Multiaxial Fatigue Analysis of Structures Submitted to Random Vibrations, Proceedings European Conference on Spacecraft Structures Materials and Mechanical Testing, 1999, Braunschweig, ESA SP-428. [3] Fuente, E.D.; Sanz, M.A.; Hernando, J.L., Exact reliability calculation with quadratic failure indices in random vibration. Engineering Structures, 2010, Volume 32, Issue 3, 793-799, ISSN 0141-0296, https://doi.org/10.1016/j.engstruct.2009.12.006. [4] Thelemann, S.; Schatz, M.; Jentsch, M.; Kommer, A.; Duddeck, F., Composite Strength Analysis under Random Loading. Proceedings European Conference on Spacecraft Structures Materials and Environmental Testing, 2023, Toulouse.