A subject matter expert is a person with deep knowledge of a specific process, product, system, material, or operational area. In manufacturing, the term commonly refers to someone whose experience is used to explain how work is performed, why controls exist, and what details are important for quality, safety, traceability, or system accuracy.
Subject matter experts are often involved in creating or reviewing work instructions, training content, process documentation, troubleshooting guides, data definitions, and system requirements. For example, an experienced operator, manufacturing engineer, quality inspector, planner, or maintenance technician may act as the SME for a defined area of work.
An SME is not automatically the process owner, document approver, or final authority. In regulated or quality-sensitive environments, SME input is commonly routed through engineering, quality, training, or document control before it becomes controlled content or formal instruction.
The abbreviation SME can also mean small or medium-sized enterprise in business contexts. In manufacturing documentation, training, and systems work, it usually means subject matter expert unless the context indicates otherwise.