For some time now, Lapp has had the idea of a cable drum that not only monitors the removal of cable lengths, but also automatically reorders if the quantity falls below a defined minimum. Why? Customers had reported to Lapp employees from time to time that they lacked an overview of their own cable stock. One customer, for example, ran out of an important cable at the most inopportune moment, bringing machine construction to a standstill. The company had to pay one percent of the machine value per week of delay as a down payment, which quickly added up to costs of several thousand euros per week.

Due to the recognized needs of the users, the project for intelligent cable inventory management was therefore taken up again and the system called 'eKanban' was further developed in close cooperation with customers.

But how does a cable drum know how much cable it contains? If the warehouse staff at some companies don't know how much cable length is left, how is a wooden drum supposed to know? What sounds like a joke actually kept the innovation team at Lapp busy for quite a while. Initially, distance sensors were supposed to provide information on how much cable had been removed from a drum and how much was left. However, this method proved to be too imprecise. In the second version, the project team used an inertial sensor that measures the revolutions of the drum and calculates the amount of cable removed.

"Instead of 10 to 15 percent inaccuracy, the new technical solution gives us a deviation of ±1 percent - which is more than acceptable for the intended application," says Dominik Schmalzried, Global Business Process Owner Digital Innovation at Lapp. The company therefore patented the solution. It consists of the inertia sensor on the cable drum or axle and a display attached to the drum rack. The main artery is a web-based dashboard in which not only the customer's fitters but also purchasers, for example, have convenient access to all cable stocks from their workstations. The sensors, which have a very long battery life, can be easily retrofitted to existing cable racks and drums. There is also a connection to digital systems from Lapp. The 'eKanban' will also offer interfaces to ERP systems as it is developed to series maturity - in line with the motto: Industry 4.0 for cable inventory management. This means that the system will soon also modernize cable inventory management for racks and reels from other suppliers.

Automatic reordering

The display attached to the drum rack shows the current cable inventory.

© Lapp

The system can be configured and controlled on a digital dashboard. Users can always see the fill level of all cable drums almost in real time. They can also set a threshold value for automatic orders. If the system is connected to Lapp, the order date can be set up flexibly: The data collected by the sensors helps to predict how much cable length will be used in a given period. The system checks in the Lapp system how long a delivery will take at this time. By comparing the consumption and delivery forecast data, the system can then schedule the reorder so that replenishment is available on time.