The present invention relates to methods and systems for determining operating and/or dimensioning parameters of a gas treatment plant including at least one gas treatment unit as well as methods and units for generating a request to initiate the determination of operating and/or dimensioning parameters of a gas treatment plant. The present invention further relates to a computer program and non-volatile or non-transitory storage medium with the computer program, which when executed on one or more processors, performs one or more of the methods.