A cycle: a repeating period or a series of stages/processes (e.g., life cycle, production cycle).
製品の品質を上げるために生産サイクルを見直した。
We revised the production cycle to improve product quality.
睡眠サイクルが乱れると体調を崩しやすい。
If your sleep cycle is disrupted, you're more likely to get out of sorts.
その業界では製品のライフサイクルが非常に短い。
In that industry, product life cycles are very short.