work in progress (WIP)

Work in progress (WIP) commonly refers to partially completed product in a manufacturing or repair process. It is material, assemblies, or work orders that have been released into production but are not yet finished goods.

What work in progress includes

In industrial and regulated manufacturing environments, WIP typically covers:

• Work orders or jobs that have been released and started on the shop floor
• Subassemblies at intermediate steps in a routing or traveler
• Kitted components that have been issued to a job and are in active build
• Units held at in-process inspection, test, or MRB while still part of the build cycle

WIP usually excludes raw materials not yet released to a job and finished goods that have completed all required operations, inspections, and documentation.

Operational view of WIP

From a systems perspective, WIP is tracked across ERP, MES, and shop-floor systems as orders move through routings, work centers, and inspection points. Typical attributes used to manage WIP include:

• Current routing operation and work center
• Quantity started, in process, completed, and scrapped
• Configuration, revision, and effectivity of the design and traveler
• Status holds, NCRs, or deviations associated with the units

In high-mix, regulated production, WIP visibility is closely tied to change control, configuration management, and traceability requirements. Design changes or new configuration variants can fragment WIP into multiple small populations with different routings, tools, and inspection states, affecting planning and backlog risk.

Financial and planning meaning

In accounting and planning, work in progress is often treated as an inventory category between raw materials and finished goods. It may be valued based on material consumed, labor applied, and overhead absorbed up to the current operation.

Planners and schedulers use WIP levels and locations to understand:

• Where capacity is being consumed
• Where potential bottlenecks or queues are forming
• Which orders are at risk relative to due dates or milestones

Common confusion

• Work in progress vs. work in process: In many manufacturing contexts, the two terms are used interchangeably. Some organizations prefer one term for financial inventory and the other for operational status, but this is not universal.
• WIP vs. backlog: Backlog typically refers to work that is ordered but not yet started. WIP refers to work that has already entered the production or repair process.
• WIP vs. WIP limits (Lean/flow): WIP is the actual in-process work; WIP limits are policy or system constraints set to cap the amount of in-process work in a cell, line, or value stream.

Context in regulated environments

In regulated manufacturing, WIP management often requires alignment between PLM, ERP, and MES so that in-process units are built and inspected against the correct design revision, configuration, and documentation set. Poor control or visibility of WIP can increase risks of misbuilds, rework, NCRs, and schedule disruption, especially when frequent design changes or multiple configuration variants are present.