1. A method for automatically determining a throughput of a process tool, the method comprising: identifying functional entities of said process tool by monitoring tool messages created by said process tool during operation, wherein the tool messages indicate activities of a number of functional entities; identifying one or more material flows as a sequence of process steps performed by at least some of said functional entities, wherein identifying said one or more material flows comprises determining whether the number of functional entities of a first material flow is the same as a previously determined number of functional entities of a second material flow; determining a process time interval for each of said process steps of said one or more material flows; and determining a throughput of said process tool for a selected process scenario for said one or more material flows by using said determined process time intervals.