Abstract: The relief organizations work in volatile environments involving a variety of actors with different skills and knowledge. The service of emergency for victims of natural disasters requires a rapid decision-making. The objective of the approach presented in this paper is to develop a Systemic Process Model (SPM) for procurement decisions in humanitarian logistics. The SPM aims to support procurement tasks of humanitarian organizations during the response phase in disaster relief. The approach provides a decision support tool using an appropriate quantitative model reflecting the specific area of humanitarian logistics processes.