🏭 WIP, or Work in Progress, refers to all partially processed products that are in progress in the production flow, but have not yet been completed. Controlling WIP is essential to ensure fluidity, quality, and operational efficiency.
Good WIP control is like a traffic light in the factory — it helps maintain the pace without congestion.
📦 Examples of WIP in Practice
- Electronic boards awaiting functional testing
- Products that have gone through assembly but are not yet packaged
- Items between pre-test (ICT) and post-test (FT or vision)
- DUTs accumulated in queues between stations
- DUTs awaiting rework
📉 Why is Excess WIP a Problem?
| Negative Impact | Effect on Production |
|---|---|
| Increased lead time | Products take longer to be completed |
| Loss of traceability | Difficulty in knowing the status of each DUT |
| Risk of damage or loss | Parts outside their standard flows |
| Difficulty in prioritization | Which products are urgent? Where are they? |
| Impact on quality | Rework of forgotten or poorly stored DUTs |
✅ Advantages of WIP Control
- Improves continuous production flow
- Facilitates traceability by batch, serial number, or operator
- Reduces the need for manual buffers or temporary storage
- Helps identify bottlenecks and balance the line intelligently
🔧 How AJOLLY Testing Implements WIP Control
At AJOLLY Testing, WIP is treated as a strategic part of the production flow. Our solutions integrate test benches, MES, and dashboards for real-time monitoring of each DUT’s status.
Applied Tools:
- Barcode reading before and after testing
- Dashboards with WIP status by stage (e.g., “in testing”, “awaiting retest”)
- Systems with automatic release of the next stage after successful testing
- Integration with Andon systems for accumulation signaling
- Report generation by operator, line, product, or batch
🔄 WIP and Lean Production (Lean)
WIP is one of the 8 wastes of Lean. The goal is to minimize it as much as possible without compromising the flow. Ideally, each DUT should flow through the line with the least possible time and with full traceability.
Controlling WIP is about keeping production fluid, predictable, and traceable. It ensures that each DUT receives attention at the right time — and with the required quality.