The objective of this paper is to present a modeling procedure, based on the use of statistical methods, to develop predictive models for Information Technology (IT) capacity planning. The goal of these models is to be able to predict IT variables’ behaviour, using initial inputs provided by high-level business explanatory variables. The modelling process consists in two main sequences, exploration and explanation, divided into modelling steps, which mix qualitative and quantitative analyses. The modelling process builds a progressive understanding of relationships among the different levels of the IT architecture. The final outcome is a statistical model, linking IT resource utilization to manufacturing activities variables. An application of the modelling process is developed in the context of the STMicroelectronics information system. As a result, two predictive models which focus on subsystems of the whole information system, link the physical servers’ daily use to manufacturing variables such as level of production, manufacturing processes deployment and fabrication throughput.