item master

An item master is the authoritative list of items, parts, and materials that a manufacturing or service organization buys, makes, stocks, or sells, along with the core data needed to identify and manage those items across systems.

What an item master typically includes

In regulated and industrial environments, the item master usually contains structured attributes such as:

• Item identifier data, such as internal part number, description, and revision or version
• Classification data, such as item type (make/buy, assembly/component, raw material), product family, and commodity codes
• Planning and inventory data, such as units of measure, lead times, reorder rules, stocking policies, and MRP parameters
• Commercial data, such as standard cost, price lists, primary supplier, and purchasing details
• Compliance and control flags, such as export control indicators, shelf‑life, hazardous material flags, and quality status

The item master record is usually created and governed in ERP or a closely integrated system, and then referenced by execution systems like MES, PLM, QMS, and warehouse management for day-to-day operations.

How it is used operationally

Operational systems depend on the item master as the single source of truth for identifying what is being planned, produced, moved, or inspected. Common uses include:

• MRP and materials planning using item lead times, lot sizes, and planning policies
• Work order creation and routing selection based on item type and revision
• Quality inspection plans and FAI/AS9102 setups that reference specific item numbers and revisions
• Traceability and genealogy records that tie as-built or as-maintained data back to a defined item
• Supplier management and purchasing that rely on consistent item identifiers and descriptions

In many organizations, detailed execution attributes such as operation-level instructions, test results, and as-built traceability are kept in MES or related execution tools, while the item master in ERP holds the stable, cross-functional attributes for each part.

Common confusion

• Item master vs. BOM: The item master describes individual items and their attributes. A bill of material (BOM) describes the structure and relationships between items in an assembly. BOMs reference item master records but are not the same as the item master.
• Item master vs. material master: Some ERP systems use “material master” as a broader term that includes both item identification and many related views (purchasing, sales, accounting). In practice, “item master” often refers to the core identification and planning attributes for parts and materials.
• Item master vs. part master in PLM: PLM may manage engineering part definitions and revisions, while ERP manages the commercial and planning view of the same item. Clear synchronization between PLM part data and ERP item master data is a common integration requirement.

Context in aerospace and regulated manufacturing

In aerospace and other regulated sectors, the item master is central to separating ERP and execution responsibilities. ERP typically manages the item master as the contractual and financial definition of the part, while MES, digital travelers, FAI tools, and NCR systems handle detailed routing, work instructions, inspection results, and as-built records that reference those item numbers and revisions.