RFID in production: Knowing which station a work order is at

When a customer asks about the status of an order, the sales team calls the production manager; the manager walks a lap of the line and says “let me go and look.” By the time the answer comes, the situation has already changed. The problem is not a lack of information, but that the information is scattered across papers, boards and people’s memories on the production floor.

Work order tracking with RFID means that the passes of the product or part tied to a work order through stations are recorded automatically from tag reads, so you can see live which stage production is at. In this article we explain how the method works, which questions it answers and what needs to be designed before starting, based on the production tracking approach within RFID & IoT Systems.

The problem with manually entered production data

• The operator’s real job is to produce; entering records takes second place in the middle of the work, and the data is entered in bulk at the end of the shift.
• Data entered in bulk describes the past, not today. Which station a product is waiting at right now is not visible.
• Semi-finished goods piling up at a station are noticed only when someone looks at the line; the bottleneck shows up not when the report comes out but when things jam.
• Notes kept by different people on the same product do not agree; which record is right becomes a matter of debate.

How does an RFID movement match a work order?

In the YazSis production tracking system, work order, station, operation, product and time information are matched with RFID movements. When a tagged product or carrier unit enters a station’s reading field, the system links the movement to the relevant work order and operation. A typical flow works like this:

1. Link the tag to the work order. The RFID tag on the product, batch or carrier unit is matched with the work order record.
2. Define the reading points. At the entry or exit of which station reading will take place is configured together with the operation rule.
3. Record the movement automatically. When the product passes through the reading field, the station, operation and time information is posted to the record; no separate manual entry is needed for the pass.
4. Filter out repeated reads. Consecutive reads of the same tag are treated as one movement, and reads that do not fit the expected flow are flagged for review.
5. Follow the status live. Management sees on screen which stage the work order is at and how long it has been waiting at which station.

Which questions can management answer?

Once movements become a single chain of records, questions that used to be answered by walking the line are answered from the screen:

• Which station is this work order at right now?
• Where is work piling up, and which operation is causing the wait?
• How long did an operation take on past jobs, and where does the gap with the plan open up?
• When a customer asks about order status, can the sales team answer without going to the production line?

The main gain here is that waiting time becomes visible. Production time is made up not only of time spent working; the time a product waits for the next station also takes up a large share. In manually kept records these waits often stay invisible. When movements come from reads, you can see on the same screen in front of which station work is piling up, which operation is falling behind the plan and which work order has silently stopped. Management takes action the moment it sees work accumulating, instead of waiting for an incident report.

Monitoring production does not mean walking the line; it means letting the line record its own movement.

How it differs from barcodes or manual records

Barcodes or manual records can also track work orders, but they require a person to scan or write at every pass. When production gets busy, this step is the first to be skipped. With RFID, reading happens by itself as the product passes through the reading field; keeping the record no longer depends on the operator’s attention. On the other hand, RFID does not give the same result in every production environment. Metal surfaces, liquids and nearby stations affect reading; that is why the setup is done by measuring and calibrating on site.

What to design before you start

RFID-based production tracking is a site design before it is a software installation. The following decisions should be made at the start of the project:

• Where will the tag sit? On the product itself, on a hanger, in a basket, a crate or a pallet? Whether the tag stays with the product along the line must be determined.
• Where will the reading points go? Will every station be monitored, or only critical passes? A reading field must not read the neighboring station.
• What are the site conditions? Metal surfaces, liquids and surrounding devices affect read quality; measurement and calibration are done on site.
• How will it relate to existing software? Which system will the work order information come from, and which system will the movement data go to? This flow is determined with the needs analysis within the project scope.

Start small

The healthiest start is a single line or a single product family. In the first weeks the goal is not reporting but seeing that reading works reliably: are tags matched to the right work order, do reading points pick up the neighboring station, are repeated reads filtered correctly? Once reading becomes reliable, waiting times and bottlenecks show up on the screen anyway; expanding the scope gets easier after that. If you would like to design a pilot for your own production flow, you can start from the RFID & IoT Systems page.