Witron modernises huge DC

Kroger and Witron have a long-standing partnership of more than 15 years with nine successfully implemented automation projects to date. Kroger was Witron's first customer in the US food retailing market, and the first company in the world to implement Witron's fully automated logistics and picking system OPM (Order Picking Machinery). Today, Witron's systems are used in Kroger’s food retail business, drugstore sector, its dry goods assortment, and its fresh and frozen goods area.

Witron recently completed the largest modernisation project at Kroger - a project with challenging tasks and an extremely tight time schedule. Witron's refurbishment experts had only 4 months to implement modernisations to the outdated replenishment warehouse located in Layton - a system with 12,800 pallet locations that was originally designed and implemented by a competitor 24 years ago.

After working on the design, time scheduling, and emergency concept design, the Witron team around Brian Sherman started to replace the seven stacker cranes. These were replaced by six new 82 foot tall Dambach devices with pivoting shuttle fork. The seventh aisle of the warehouse with a length of 394 feet remained clear to enable better accessibility to the system for future maintenance tasks and to allow Kroger a path around the automated system. The new stacker cranes were integrated into the existing rack supported high bay warehouse and are able to transport any North American GMA pallet without additional system pallets while having a high inbound / outbound throughput of 46 single cycles (inbound / outbound) per stacker crane. The original front-zone inbound / outbound conveyor system was exchanged and replaced by state-of-the-art technology from the company Binder.  

The existing customer’s S5 controls were replaced by current S7 control technology. A new Witron material flow computer (MFC) will now coordinate all conveyor system movements. Moreover, Kroger decided in favor of a state-of-the-art Witron WMS solution to manage the high bay operation instead of the previously used warehouse management system from a US provider. In addition to the assembling and dismounting tasks, Witron - as general contractor - coordinated all necessary work steps with suppliers and customers. "Even though the existing logistics center wasn't originally implemented by Witron, we were able to rapidly become acquainted with all work details based on our extensive refurbishment know how", according to Brian Sherman. "This was essential in order to meet the tight timeline". 

Modification during ongoing operation

The modification and start-up works for the replenishment warehouse were executed during normal operation - during night shifts, on weekends, and during non-operating times. "The Layton warehouse supplies several hundred Kroger stores. Therefore, it was extremely important to maintain smooth operation during our refurbishment efforts, as Kroger is a quality brand in the US and stands for high store service", explains Brian Sherman. And based on that, the Witron experts decided to replace the components step by step. "The crucial success strategy was the mechanical de-installation and new installation of the stacker cranes in pairs, including the corresponding inbound / outbound conveyor system - and the parallel start-up of the PLC and the MFC with subsequent go-live", says Sherman.  

Trust has been proven

"Although we knew that Witron modernised numerous systems in different industries and of different sizes across the globe, so far, we knew the company largely as general contractor for our nine mechanisation projects where we are using their most innovative picking technology," according to Kroger project manager Steve Kelly.

"With regards to modernisation projects, we only had a few contact points to Witron - as all of our Witron projects had been new system implementations. However, we wanted to hear Witron's approach for such a process, in parallel with the discussions we had with other automation vendors.

"Our trust was rewarded. The project was completed on time, and our warehouse employees and the customers at our stores did not experience any disruption to their normal routine.”