処理 and 作業: an object handled and a task performed
Compare used oil and data processing with tool inspection before dangerous work and a completed cleanup, preserving elapsed time, preparation, and outcome.
処理: handling oil and processing data
処理 (しょり) means handling or processing. 「使い終えた油を適切に処理した。」 means “We disposed of the used oil properly.” Used oil was disposed of properly. The example states the object and a past action, without specifying a disposal method or a procedure for an actual site.
「大量の資料を処理するのに一週間かかった。」 means “It took a week to process the large volume of data.” Processing the large volume of data took a week. 一週間かかった gives time spent processing, rather than a plan to start in a week's time. Oil and data are different objects in separate examples.
作業: pre-work inspection and cleanup
作業 (さぎょう) means work or task. 「危険な作業を始める前に道具を点検した。」 means “We inspected the tools before beginning the dangerous work.” The tools were inspected before beginning dangerous work. Inspection is the action that occurred; 始める前に places it before the work, rather than reporting that the dangerous task was completed.
「皆で分担したので片付けの作業が早く終わった。」 means “Because everyone shared the duties, the cleanup finished quickly.” The cleanup finished quickly because everyone shared the duties. 分担したので connects the shared work with the quick finish, without making this cleanup the dangerous task in the other example.
Distinguish duration, preparation, and completion
The 処理 examples focus on handling an object such as oil or data; the 作業 examples focus on a work activity. These can be related, but the actions, duration, and results of separate examples should not be transferred between them.
Compare the week spent processing, the inspection before work begins, and the quick completion of cleanup. An elapsed duration, a preparatory action, and a finished activity provide different kinds of information.
What is stated by a week spent on data 処理, inspecting tools before dangerous 作業, and a cleanup 作業 that finished quickly?
Show the answer and why
They state processing duration, a pre-work inspection, and completed cleanup resulting from shared duties. The inspection is not completed dangerous work, and the cleanup's outcome should not be transferred to that separate task.