RFID & Work-in-Process

Work in Process, also called Work in Progress and WIP, is the term for partially completed goods that are being made or finished within a facility. Most of the time, work in progress goods are located in manufacturing facilities, but they can also be in casting houses, lay down yards, or other production facilities. The WIP process usually lasts from the raw material stage, all the way to the finished product, which could take hours, days, or even more time. It’s important for these companies to keep track of the number of items within their facility at all times because those goods are their inventory, and if they are lost or stolen, it costs the manufacturing company money. Unfortunately, because these partially completed goods go through intense processes during WIP, it’s often difficult to differentiate, track, and locate specific items within a large manufacturing facility.

In typical RFID applications, RFID tags can be adhered to, embedded in, or attached to the specific item/asset/product, but because of the processes that some WIP items go through, this isn’t always possible. Examples of those processes are:

  • High temperature processes, like welding, sterilizing, and laundering
  • Rugged processes, like cutting, hammering, and molding
  • Water-based processes, like rinsing, disinfecting, and painting

Before we go into how RFID is used in WIP facilities, let’s walkthrough why RFID is needed and what benefits it adds.

RFID’s Benefit in WIP

Overall, Work in Process can benefit from RFID in these ways:

  • Increase efficiency
  • Near real-time location & tracking
  • Automatically capture data
  • Reduce manual processes, increasing accuracy
  • Reduce errors
  • Provide increased visibility
  • Provide timestamped reporting data

Similar to other uses of RFID technology, RFID can benefit WIP applications by uniquely identifying and tracking inventory items from the beginning stage, to the finished product. This is called WIP tracking, and RFID can enable near real-time inventory accuracy in all stages of production. The ability to have this level of insight into where all partially completed items are within the manufacturing process can be used to ensure the facility is working efficiently and effectively. For example, if 5 items are in the pre-production stage today, and they average number in that stage each day is generally around 30 items, the RFID system can alert the appropriate personnel via software and/or a visual cues like a colored stack light.

In addition, RFID tags on WIP goods can ensure that the item has been to all the appropriate stations and is ready to be shipped or installed into the finished product. For instance, in car manufacturing facilities, a car that will have 4-wheel drive might need to visit an extra manufacturing station for additional parts while it travels through the facility. If each car’s RFID tag is read at each parts/manufacturing station, the company can be 100% positive that the car received all the necessary parts it needs in order to be labeled as a 4-wheel drive vehicle. Adding another layer of granularity (I.e., where the item is on the line) allows the manufacturer to have item-level traceability throughout the entire process. Having access to this data makes it easier to point to problematic areas on the line that are causing recalls, or even to dispute warranty claims.

This can also be done with barcodes; however, scanning a barcode is a manual process that can often be accidentally skipped by station operators, making RFID ideal.

How are Assets tracked in WIP Applications?

As mentioned above, some WIP goods must go through stringent processes throughout the facility, so they cannot have an RFID tag adhered or attached. Instead, some WIP tracking is accomplished by attaching an RFID tag to the bin, cart, or AGV that the WIP goods travel in/on throughout the facility.

By attaching a reusable RFID tag to the bin or cart that is uniquely encoded, you can effectively keep track of the item and avoid some of the more rugged processes involved in the manufacturing facility. Once a WIP item has been assigned to a bin/cart, that uniquely encoded number is associated with that item in a database. This could be an on-premise database or one hosted in the cloud that contains information about that WIP item like type of item, customer, important dates, etc.

After the particular WIP item has been completed, the tag on the bin/cart will then be unassociated with that item in the database, and re-associated with a new WIP item and start over from the beginning.

RFID hardware is placed in certain areas of the facility such as at important stations in order to read the RFID tag to confirm that the partially completed item arrived at the station. The read data from all of the stations can be used to accurately track specific items as they work their way through the manufacturing facility and guarantee that necessary processes have been completed.

How is the RFID Read Data in WIP Used?

The read data gathered from RFID systems at read points can be used for a few different purposes including:

  • Item visibility - tracking specific WIP items
  • Managing daily/monthly production data
  • Providing customers with accurate order completion estimates
  • Reporting on facility efficiency
  • Locating ineffective/slow processes /bottlenecks
  • Identifying slower or hesitant personal for additional training
  • Prevent shrinkage by keeping an automated record of movement
  • Prevent errors by triggering lights/alarms when certain items are in the wrong area
  • Provide a log of each step in production in case of faulty production / production errors

All of these purposes can have major impacts in facility such as improving efficiency, visibility, reporting data, customer satisfaction as well as preventing shrinkage and errors.


Thanks for reading this article all about how RFID can benefit Work in Progress. For more information on WIP, comment below or contact us!