A system for supplying a reagent to multiple tools in an electronics fabrication facility is configured using a demand probability distribution. In specific examples the reagent is a non-atmospheric or a specialty gas and the demand probability distribution is developed using Monte Carlo statistical techniques. In one embodiment, a method for configuring a reagent supply system for an electronic device manufacturing facility is provided. The method includes (a) collecting representative information for process tools within the fabrication facility which use the reagent; (b) creating a simulation of process tool operation to model an overall demand profile for the process tools; (c) creating a statistical probability distribution of the reagent demand by the process tools using data from the model; and (d) correlating data from the probability distribution with supply system characterization data to configure the supply system.