Components mounted on rotating machinery with varying speed such as engines or gear boxes will be submitted to deterministic loads coming from the machinery itself and possibly also to random loads such as the road profile or the air flow. Such a composite mechanical environment is traditionally defined as either swept sines or random profiles. In this webinar, we will present a methodology which enables the test engineer to superimpose swept sines and a power spectral density of acceleration to optimize and accelerate the durability tests of such components.