Method for detecting and quantifying obstructions in a gas network under pressure or vacuum; the gas network comprising : - one or more sources of compressed gas or vacuum; - one or more consumers , consumer areas of compressed gas or vacuum applications; - pipelines or a network of pipelines to transport the compressed gas or vacuum from the sources to the consumers , consumer areas or applications; - a plurality of sensors which determine one or a plurality of physical parameters of the gas at different times and locations in the gas network ; wherein the method comprises the following phases: - a baseline or zero phase determining an initial physical model or mathematical relationship between measurements from a first group of sensors and a second group of sensors based on physical laws using estimation algorithms; - an operational phase in which the physical model or mathematical relationship between the measurements of the first group of sensors and the second group of sensors is re-established at regular time intervals by means of estimation algorithms to predict gas network obstructions ; wherein the operational phase comprises the following steps: - reading out the first group and second group of sensors ; - re-estimating, determining or calculating the physical model or mathematical relationship on the basis of the read measurements from the sensors ; - determining or calculating of the existence of an obstruction in the system based on the difference and/or its derivatives between the parameters of the physical model or mathematical relationship as determined during the baseline or zero phase and the operational phase ; - generating an alarm and/or generating a degree of obstruction and/or generating the corresponding obstruction cost if an obstruction is detected wherein the aforementioned physical model or mathematical relationship takes the form of a matrix of parameters or constants, wherein the modifications of these parameters or constants are being monitored during the operational phase . - one or more sources of compressed gas or vacuum; - one or more consumers , consumer areas of compressed gas or vacuum applications; - pipelines or a network of pipelines to transport the compressed gas or vacuum from the sources to the consumers , consumer areas or applications; - a plurality of sensors which determine one or a plurality of physical parameters of the gas at different times and locations in the gas network ; - a baseline or zero phase determining an initial physical model or mathematical relationship between measurements from a first group of sensors and a second group of sensors based on physical laws using estimation algorithms; - an operational phase in which the physical model or mathematical relationship between the measurements of the first group of sensors and the second group of sensors is re-established at regular time intervals by means of estimation algorithms to predict gas network obstructions ; - reading out the first group and second group of sensors ; - re-estimating, determining or calculating the physical model or mathematical relationship on the basis of the read measurements from the sensors ; - determining or calculating of the existence of an obstruction in the system based on the difference and/or its derivatives between the parameters of the physical model or mathematical relationship as determined during the baseline or zero phase and the operational phase ; - generating an alarm and/or generating a degree of obstruction and/or generating the corresponding obstruction cost if an obstruction is detected <EOS>