inefficiency
Refers to the state or quality of being inefficient, often in work, systems, or processes.
この部署の非能率が問題になっている。
The inefficiency of this department has become a problem.
非効率 is a near-synonym also meaning 'inefficiency', but 非能率 is less common and may sound slightly more formal or technical.
非能率 describes a lack of efficiency (being inefficient), the direct opposite of 能率's sense of efficient, productive work.
Formed from the prefix 非 (hi-, 'non-') and 能率 (nōritsu, 'efficiency').