1. A method for identifying constraints on reducing consumable usage comprising: acquiring print job information for a set of print jobs submitted for printing by a set of users, each print job comprising a document to be printed; computing a print job representation for each of the print jobs based on features extracted from the print job information; providing for user-annotation of the submitted print jobs with a task category and a constraint category, each of a plurality of task categories representing a respective task with which the printing of a print job is associated, each of a plurality of selectable constraint categories expressing a different reason for printing the print job; receiving user-annotations for at least some of the submitted print jobs; clustering the print jobs into clusters based on the print job representations and task category annotations; and generating a representation of the set of print jobs which represents reasons for printing of print jobs in at least one of the clusters, based on the users' constraint category annotations, wherein at least one of the computing of the print job representation, providing for user-annotation, receiving user-annotations, clustering the print jobs, and generating of the representation of the set of print jobs is performed with a computer processor.