A brief overview of the texture-residual stress relations is presented together with some simulations, including both the calculation of the X-ray Elastic Constants (XECs) and the modelling of a through-thickness planar residual stress in fibre-textured thin films. Advantages and limits of the X-ray Residual Stress Analysis (XRSA) are discussed, also in relation to the underlying hypotheses. Thin film homogeneity in particular can be a severe limitation to describe real systems.