Slakey Brothers - Horizontal Carousels Boost Order Picking Efficiency & Accuracy

Slakey Brothers, established in 1939, is one of the West Coast’s largest distributors of heating, ventilation, air conditioning, and plumbing supplies.

Application: Distribution of HVAC, and plumbing supplies to the company's wholesale branches, retail stores and contractor job sites.


Equipment: Four horizontal carousels with three integrated as a pod (workstation), pick-to-light system.


Summary: The DC has improved order picking efficiency by almost 400% without adding staff and hitting their ROI in under two years.


By using a simple approach to automated storage and retrieval operations, Slakey Brothers of Elk Grove, California has been able to improve its order picking efficiency almost 400% while handling a 25 percent increase in business.

Slakey Brothers, established in 1939, is one of the West Coast’s largest distributors of heating, ventilation, air conditioning, and plumbing supplies. In order to improve its distribution capabilities and meet anticipated increases in business, the company built a 300,000 square foot distribution center where it maintains some 24,000 active SKUs with 18,000 on hand. Today, the distribution center serves 31 wholesale branches and three retail stores in four states.  Slakey Brothers also supplies contractors through their local stores, directly to job sites or to the contractors’ shops.  A fleet of approximately 100 private trucks delivers 90 percent of the orders within 200 miles of the distribution center.

The center was designed with high-rise pallet racks to store the wide range of various shaped items that are kept on hand. Orders are picked from the pallet racks in batches using wire-guided order picking vehicles and lift trucks that are directed by the company’s warehouse management system.

“The picking rate for small to intermediate sized items was below what I thought we needed for efficient operation,” said Sean Burke, Slakey Brothers Corporate Logistics Manager.

The system installed by Slakey Brothers uses three KardexRemstar horizontal carousels integrated as a pod (workstation) and equipped with a pick-to-light system and software.  Horizontal carousels are a system of bins and shelves that rotate on an oval track, delivering stored items to an operator on command.

Flling Sales and Store Orders
The Slakey Brothers distribution centers fill two types of orders which are sales orders and store/branch orders.  Sales orders are orders delivered to local contractor customers.  Slakey Brothers fills about 300 sales orders daily from their DC.  The second type of order is a store/branch order. This is essentially a warehouse transfer that is used to replenish Slakey Brothers store locations.  A master store order is comprised of approximately 50-150 line items. To fill these orders, Slakey Brothers creates a batch of four store orders that are picked simultaneously. On average 16 – 20 stores orders are processed every day – larger stores order every day while smaller stores are two to three times per week.
Improving Picking Accuracy
To begin a batch pick, the operator scans a tote’s license plate (bar code) linking a specific sales order or master store order to a specific tote.  The operator repeats this process for each of the orders being batch.  The three horizontal carousels automatically pre-position themselves to be picked.  KardexRemstar’s Light Tower pick-to-light system tells operators at a glance which carousel and shelf to pick from and the number of items to pick, facilitating productivity and virtually eliminating picking errors.

The horizontal carousel pod includes a raised carpeted platform for operator comfort and safety during order-filling operations.  Should an operator step off the platform for any reason, a safety mat system activates the system’s e-stop.

A fourth horizontal carousel stages empty totes.  A pallet dispenser and pallet conveyor deliver empty pallet-sized folding bulk boxes to the pod.  Each bulk box accommodates a single store master order or four sales orders in four totes.  When order picking is completed, the bulk boxes are delivered via a pallet conveyor to the shipping department and off-loaded by a lift truck.

A gravity pallet conveyor delivers new inbound freight and replenishment material to the Pod via a chain transfer to the main pallet conveyor.

“Since the installation of the horizontal carousel system, we have increased productivity from picking 40 lines per hour to picking 150-160 lines per hour,” Burke said.  “Even with a 25 percent increase in our business, we have been able to reach this high picking efficiency level without having to add staff.  In fact, we’ve been able to reassign some operators to other duties,” he said.
As an added benefit, the compact design of the KardexRemstar horizontal carousel system requires only 1,800 square feet of floor space compared with 4,000 square feet of floor space required by the pallet rack system.

“The horizontal carousel system has met our expectations for improved order picking efficiency,” Burke said. “We are on track to realize our return on investment in less than two years.”