Manufacturers must assure the reliability of their products, what implies guaranteeing optimal working conditions during their service life. In this work, a methodology is proposed to estimate the damage experienced by a component under non-proportional loading to be made aiming at predicting when the component will fail and where the failure location will happen. In the present case, a novel cyclic counting model is introduced based on a hybrid variant of the rainflow algorithm applied to the results of the Papadopoulos critical plane approach using the Basquin fatigue model. In this way, the damage model is achieved.