Refractory transition metal nitrides are attracting attention in many microelectronics research and development fields. Their different applications and desired performances require a precise control of the film thickness and elemental depth profile. This information can be non-destructively obtained combining Grazing-Incidence X-ray Fluorescence (GIXRF) and X-ray Reflectometry (XRR) analysis. GIXRF-XRR joint analysis can be performed following a reference-free approach,- which requires the knowledge of the whole experimental system. However,- such a rigorous metrological approach cannot be easily applied to in-lab or in-fab tools due to the difficulty to access the various experimental set-up parameters,- therefore another approach is needed. In this paper,- we used a reference-based method consisting in the use of known standard samples,- close in composition and structure with respect to the samples to analyse,- to deduce the key parameters of the instrumental setup. These are then used to perform quantitative GIXRF-XRR combined analysis of the samples of interest. We applied this method to titanium tungsten nitride thin films elaborated by Physical Vapour Deposition (PVD). Our results show that the reference-based method,- using carefully determined instrumental functions,- can meet the requirement for both qualitative and quantitative depth-profiling analysis. The reference-based approach result easier to implement into labs and fabs than the reference-free method. © 2020 Elsevier B.V.