Materials handling and replenishment

The ARCX Watbox™ monitors material use, automatically requesting replenishment, and can expand into an intelligent electronic kanban system.

  • A workcell starts with 50 widgets in a parts bin.
  • As the operator uses parts, a simple light curtain or opto-sensor triggers the Watbox™ to decrease the count of parts in the bin.
  • At a preset level, the Watbox™requests more materials from the upstream process or material stores.
  • A connected bar-code reader, built-in badge reader, and native connectivity to a database or ERP system for material traceability, throughput information, prioritized replenishment, all in real-time, at low-cost. Read below for more details…

Material Handling and Replenishment or 'e-Kanban'

The 'kanban' system is one of the basic elements of a pull-production system and lean manufacturing. Kanban substantially improved the production process in reducing raw inventory, WIP and smoothing out production flow. Balance is essential; too much inventory, versus someone sitting idle or bringing the line to a halt, are the outcomes of a system out of balance.

Now the kanban process itself can be improved with 'e-kanban' through the use of the Watbox™.

The basic idea of the kanban system is to use a kanban card or empty bin to pull WIP from the preceding work-cell or to indicate that more raw materials are needed from stores. The challenges with this method include non-productive work caused by card handling, lost cards, varying time from issuing the card to receiving a refill, and the inefficiency of someone, possibly across the other side of the plant, watching for the kanban card or empty tote.

E-kanban (or electronic kanban) improves on this by sending an electronic signal to request a refill. The signal is also a valuable piece of data yielding other benefits: no lost cards, a demand signal is immediate, it indicates throughput, minimizes stock-outs and line halts, and can signal ERP for re-ordering. It is almost essential when cycle time varies at a work-cell such as in small batch manufacturing, high-mix environments or maintenance and repair centers.

The Watbox™ and a simple program can form the basis of a low-cost, reliable, e-kanban system.

The diagram above depicts the following:

Work starts with a full bin of 50 widgets. As the operator reaches into the bin to take the next widget, a simple light curtain or opto-sensor triggers the Watbox™ to reduce the count by one each time. At a preset level (such as 10), the Watbox™ sends a trigger over Ethernet to material stores requesting replenishment.

The rate at which the operator is pulling widgets from the bin, and the remaining quantity can also tell material stores when the operator will likely run out of material, helping them prioritize their deliveries, to keep everyone working without stoppages.

Added benefits are easy to add on.

Scalability: One Watbox™ can monitor multiple parts bins.

Barcoding: Barcode scanners can plug directly into the Watbox™serial port. When the parts are delivered a barcode scanner attached to the Watbox™confirms that the correct materials were received for that work-cell and increases the quantity count of the bin.

Operator validation: the Watbox™ has a built in HID badge reader, able to log who is working in the cell or who delivered the parts and when.

Parts Cage: Placing a Watbox™at the parts cage allows for tracking parts leaving the material stores area, using the built-in HID badge reader and a connected bar-code reader.

ERP/Database interface: The Watbox™ talks natively to SQL databases or can communicate directly with business and ERP systems to help automate purchasing or replenishment from a supplier. The material usage rate can indicate productivity, expose line imbalances, help in scheduling adjustments, gives visibility where operations are spatially scattered, all in real-time, and this information falls out for free as input for ongoing improvement projects.