A method of controlling an image reproduction system, wherein a process duration for processing a reproduction job is estimated on the basis of a measured time for the processing of a number (n) of pages that have been processed already, the method comprising the steps of: - storing a digital table which contains a number of pre-defined job types as well as a respective correction factor (A; A4) for each job type; - when a job is received, assigning a job type from the digital table to the received job; - calculating a first estimate for a time needed for processing at least a specified collection of pages from the job, said first estimate being calculated on the basis of a model that reflects at least the dependency of the processing time on the number of pages to be processed; - calculating a second estimate by multiplying the first estimate with the correction factor (A; A4) that is related to the assigned job type; - scheduling the job using the second estimate; - processing said specified collection of pages; the method characterized in the steps of: - calculating a deviation of the first estimate from the processing time that has actually been needed for processing said specified collection of pages, and updating the correction factor (A; A4) on the basis of that deviation; and - storing the updated correction factor in the digital table, and in that: each job type is at least determined by a media attribute like media weight; and the digital table includes for each job type a series of pairs of correction factors (A1 - A4) and numbers (n1 - n4) of pages involved, each correction factor being an update of its predecessor in the series, a latest update of the correction factor being calculated by forming a weighted sum of an inaccuracy factor (D/D1), said inaccuracy factor (D/D1) indicating said deviation, and all the correction factors (A1 - A4) in the series, with their respective numbers (n, n1 - n4) of pages as weight factors, and the update includes discarding the oldest correction factor from the table, shifting the other correction factors (A2 - A4) by one position in the series, and entering the latest update of the correction factor as a last correction factor in the series. - storing a digital table which contains a number of pre-defined job types as well as a respective correction factor (A; A4) for each job type; - when a job is received, assigning a job type from the digital table to the received job; - calculating a first estimate for a time needed for processing at least a specified collection of pages from the job, said first estimate being calculated on the basis of a model that reflects at least the dependency of the processing time on the number of pages to be processed; - calculating a second estimate by multiplying the first estimate with the correction factor (A; A4) that is related to the assigned job type; - scheduling the job using the second estimate; - processing said specified collection of pages; - calculating a deviation of the first estimate from the processing time that has actually been needed for processing said specified collection of pages, and updating the correction factor (A; A4) on the basis of that deviation; and - storing the updated correction factor in the digital table, and in that: each job type is at least determined by a media attribute like media weight; and the digital table includes for each job type a series of pairs of correction factors (A1 - A4) and numbers (n1 - n4) of pages involved, each correction factor being an update of its predecessor in the series, a latest update of the correction factor being calculated by forming a weighted sum of an inaccuracy factor (D/D1), said inaccuracy factor (D/D1) indicating said deviation, and all the correction factors (A1 - A4) in the series, with their respective numbers (n, n1 - n4) of pages as weight factors, and the update includes discarding the oldest correction factor from the table, shifting the other correction factors (A2 - A4) by one position in the series, and entering the latest update of the correction factor as a last correction factor in the series. each job type is at least determined by a media attribute like media weight; and the digital table includes for each job type a series of pairs of correction factors (A1 - A4) and numbers (n1 - n4) of pages involved, each correction factor being an update of its predecessor in the series, a latest update of the correction factor being calculated by forming a weighted sum of an inaccuracy factor (D/D1), said inaccuracy factor (D/D1) indicating said deviation, and all the correction factors (A1 - A4) in the series, with their respective numbers (n, n1 - n4) of pages as weight factors, and the update includes discarding the oldest correction factor from the table, shifting the other correction factors (A2 - A4) by one position in the series, and entering the latest update of the correction factor as a last correction factor in the series.