1. A processing device comprising: an input unit configured to input a first processing-descriptive document; and a processing unit configured to perform processing procedures written in the first processing-descriptive document, wherein the processing unit generates a second processing-descriptive document by deleting at least one description part illustrating processing performed, so as to call a next processing device, from the first processing-descriptive document, and call the next processing device by using the second processing-descriptive document.