Glossary

WIP (Work in Progress)

WIP commonly refers to materials, parts, or units that have started production but are not yet finished goods.

Planning, Procurement and Resilience Materials Planning and ERP Integration Materials Planning / MRP

WIP (Work in Progress) commonly refers to materials, components, assemblies, batches, or units that have entered a production or processing workflow but have not yet reached their final completed state. In manufacturing, it sits between raw materials and finished goods.

The term can refer to both the physical items moving through operations and the associated inventory, status, or value recorded in business systems such as MES, ERP, or shop floor tracking tools. Depending on the organization, WIP may include partially assembled products, queued lots between process steps, items waiting for inspection, or batches in rework. It usually does not include untouched raw material or completed items that are ready for shipment.

How it is used in operations

WIP is used to describe what is currently in process on the shop floor or in a regulated production environment. It often appears in:

production scheduling and dispatch lists
inventory valuation and costing
MES route step status and lot tracking
queue, bottleneck, and throughput analysis
traceability records for partially processed material

For example, a machined part waiting for coating, a batch between mixing and packaging, or an assembly paused for inspection may all be treated as WIP.

What WIP includes and excludes

Includes: items that have started one or more defined process steps but are not complete.
Usually excludes: raw materials not yet issued to production, and finished goods that have completed required processing.
May or may not include: quarantined, reworked, or inspection-hold items, depending on local inventory and status rules.

Common confusion

WIP is often confused with finished goods, raw materials, and inventory on hand. WIP is only the portion of inventory that is actively in process or partially completed. It is also sometimes confused with a temporary task label meaning unfinished work in project management or software development. In industrial operations, the manufacturing inventory meaning is usually the relevant one.

Related FAQ

Is MES an ERP system?

No. A Manufacturing Execution System (MES) is not an ERP system. MES focuses on managing and documenting production on the shop floor, while ERP manages enterprise-level planning, finance, and resources. In regulated, brownfield plants they typically coexist, integrate, and partially overlap, which creates both opportunities and integration risks.

How do you extend a manufacturing KPI framework to tier-1 and tier-2 suppliers?

Extending a manufacturing KPI framework to tier-1 and tier-2 suppliers requires careful scoping, common definitions, contractual alignment, and pragmatic data integration. You typically cannot just push your internal dashboards outward. Instead, you need a staged model, clear data-sharing rules, validation of supplier data, and contingency plans for uneven system maturity across the supply base.

Can MES reduce safety stock levels?

MES can contribute to lower safety stock, but only when underlying process stability, data quality, and planning integration are already strong. In many regulated, brownfield plants, MES initially exposes variability and data gaps that justify existing buffers. Stock reductions are gradual, validated changes, not an automatic outcome of MES deployment.

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