An image formation apparatus receives, from a host computer, job data including image-formation data and a procedure for predetermined processing, and a computer controls image formation (printing) in accordance with the received procedure. Thereby, the image formation apparatus communicates with an external unit in accordance with the procedure, and based on a result of the communication, printing can be controlled, and by changing the content of the procedure, a control procedure for image formation can flexibly be changed. This enables detailed control of outputting, such as the restriction of the use of a printer, and the restriction of the use a printer in accordance with a user or the content of a document to be output.