The traceability among different abstraction levels in a software development process is still an unsolved problem. Our present goal is to reduce the gap between the high level abstract software product line (SPL) reference architecture (RA) and the concrete application design, by defining first traceability links between the RA components and the technological assets used by the enterprise requiring the SPL, and then study the architectural components interfaces by adapting the Domain Realization phase guidelines; they are proposed by Böckle, Pohl, and van der Linden (2005), and by the ISO/IEC 26550 (2015) reference model for SPL engineering. This preliminary work establishes links between the RA and an external configuration system to facilitate the compliance with laws, which has been found as a major problem while configuring Human Resources (HR) systems. Our approach is illustrated with an industrial case study, the Vacation Request subsystem of the SEDIT HR system of the Berger-Levrault enterprise, widely used in French and foreign communities.