Production or creation done in-house rather than outsourced. Common business term referring to internal production.
コスト削減のために一部部品を外注から内製に切り替えた。
To cut costs, we switched some parts from outsourcing to in-house production.
このシステムは内製で開発されたため、カスタマイズがしやすい。
Because this system was developed in-house, it's easy to customize.
内製化を進めることで納期管理が改善した。
Advancing in-house production improved delivery-time management.