"Where is my order?" In many factories, answering this question means a supervisor walking the floor, checking registers and asking operators. Jobs get lost between operations, sit unnoticed in queues and arrive late at the final stage. WIP tracking gives real-time visibility of every job between every operation, so status questions are answered instantly and flow problems become visible.
What WIP tracking records
- Which operation each job or batch is at.
- Status: waiting, in progress, complete, on hold, at subcontractor.
- Quantities: started, good, rejected, rework.
- Times: when each operation started and finished, and how long the job waited between operations.
- Location: machine, cell, area or storage location.
Job travellers with barcodes
The simplest reliable method is a job traveller — a printed card or label that moves with the job — with a barcode or QR code. At each operation, the operator scans the traveller to start and finish, entering quantities and rejects. Scanning takes seconds and eliminates handwriting and re-typing. See digital job cards.
WIP by stage and age
With operation booking, you can see WIP by stage: how many jobs and units are waiting at each operation. Adding age — how long each job has been in WIP and at its current stage — reveals stuck jobs. A job that has waited five days in front of heat treatment needs attention long before it delays an order.
Queue and wait time
In most job shops, jobs spend far more time waiting between operations than being worked on. It's common for processing to be a small fraction of total lead time. WIP tracking measures wait time per operation, which shows where queues build and where flow improvement would shorten lead times most.
Finding bottlenecks
Queues form in front of bottlenecks. When WIP tracking shows a growing queue at a particular machine or process, it's a signal to add capacity, reduce setups, prioritise or redirect work. Without tracking, bottlenecks are discovered only when orders are late.
Subcontract operations
Jobs sent out for plating, heat treatment or machining disappear from view in many factories. Track them out with a challan or dispatch record, with expected return dates, and track them back in with quantities. Overdue returns are flagged automatically. See job work management.
WIP, lead time and cash
Little's Law links them: average lead time equals WIP divided by throughput. If throughput stays the same, reducing WIP reduces lead time. Less WIP also means less cash tied up, less handling damage, less floor space and faster detection of quality problems. Releasing jobs to the floor only when they can actually be worked — rather than all at once — is one of the simplest ways to reduce WIP.
Better delivery promises
With live WIP status, sales and planning can answer customer questions accurately and give realistic delivery dates for new orders. Orders at risk are visible early, when there's still time to expedite.
An example: a fabrication shop
A structural fabrication company regularly missed delivery dates despite busy machines. It introduced barcoded travellers and tablet booking at cutting, drilling, welding, painting and dispatch. Within weeks, WIP data showed jobs spending days waiting before painting, because the paint shop batched work by colour and jobs were released to fabrication far earlier than needed. The company changed job release rules and introduced daily paint scheduling linked to WIP. Lead times fell and on-time delivery improved, without additional equipment.
Getting started
Print barcoded travellers for every new job, place a tablet or scanner at each main operation and ask operators to scan start and finish. Within a few weeks, review WIP by stage and age, find the biggest queues and change release rules or priorities to reduce them.
Common mistakes
- Tracking only job completion, not each operation.
- Manual entries at day end instead of scanning in real time.
- Ignoring wait times and focusing only on machine time.
- Releasing too many jobs at once, inflating WIP.
- Losing track of subcontracted operations.
How software helps
MES and shop floor software record every operation with scanning, show WIP by stage, age and location, flag stuck and overdue jobs and feed delivery dates back to planning. See shop floor management software.
Talk to us about real-time WIP tracking for your factory.
Choosing what to track
Not every factory needs tracking at every micro-step. Track at operations where responsibility changes, where queues form, where quality checks happen and where jobs leave the building. For most job shops, that means five to ten tracking points per routing, which is enough to see flow without burdening operators.
WIP limits
Once WIP is visible, set limits: a maximum number of jobs waiting at each bottleneck or released to the floor at once. When limits are reached, new jobs wait in planning rather than on the floor. This simple rule often shortens lead times more than any scheduling algorithm.
Frequently asked questions
What is WIP tracking?
Recording where each job or batch is in its routing — which operation is complete, which is in progress and where it's waiting — so status is visible without walking the floor.
How do operators record WIP movements?
Usually by scanning a barcode on the job traveller at the start and end of each operation, on a tablet or handheld scanner.
Why does WIP matter for cash flow?
WIP is money tied up in partly finished goods. Reducing WIP and lead time releases cash and reduces the risk of damage, obsolescence and rework.
Can WIP tracking show bottlenecks?
Yes. Jobs queuing in front of a particular operation show where capacity is short or where flow is blocked.
Does WIP tracking work for subcontracted operations?
Yes. Jobs sent to subcontractors can be tracked out and back, with expected return dates and balances.
