1. An information processing apparatus comprising: a processor programmed to: acquire document images of a plurality of documents; specify, based on the acquired document images, types of the plurality of documents; classify each of the plurality of documents, based on the specified type, into either: a key document as a target of one of a plurality of predetermined processings; or a relevant document required for performing one of the plurality of the predetermined processings; store the classification of each of the plurality of documents in a memory; specify a particular one of the predetermined processings corresponding to a classified key document; and in a case where a plurality of classified key documents are specified: specify a dependency relationship of processing specified for the plurality of the classified key documents among each specified key document and a relevant document related to the particular predetermined processing; determine a performing order of the processings specified for the plurality of classified key documents based on the specified dependency relationship; and cause processing of the processings of the plurality of specified key documents according to the determined performing order.