review work; study; investigation
Refers to the process of examining, studying, or investigating something, often in a formal or systematic context such as business, research, or policy-making.
We will begin the review work for the new project.
The investigation takes time.
検討 means 'examination' or 'consideration' in a general sense, while 検討作業 specifically refers to the work or process of conducting such an examination.
作業 means 'work' or 'operation' broadly; 検討作業 narrows it to work involving review or study.
Compound of 検討 (けんとう, 'examination, consideration') and 作業 (さぎょう, 'work, operation').