Quantifying MHE for a high-volume, fully automated warehouse
An international logistics firm approached CRB for assistance validating their design with a full simulation of a 140,000-sf warehouse’s automated system, including multiple subsystems for dynamic picking with pallet reserves, high volume picking via ASRS, and automated tote picking with direct-to-customer conveyance. With eight levels of high-density storage, this large warehouse boasts a capacity of ten thousand pallets and seven thousand totes, necessitating a highly complex automated material handling and intralogistics solution.
Dynamic simulations and modeling can estimate resource needs (personnel and equipment) under various warehouse operating conditions—offering an extremely beneficial data set when planning a new facility. Our simulation and operations experts regularly develop models and simulations to quantify the material handling equipment (MHE), or “robots,” needed to optimize a warehouse’s layout, schedule and productivity. However, this project would result in one of the most sophisticated warehouse models we’ve performed, yet.
The client needed to confirm that the automation system’s design and AGV count could achieve the desired throughput. They also wanted to understand the scope of potential limitations, and if modifying the AGV quantity would alleviate those limitations.
To understand throughput and utilization, the simulation evaluated four different scenarios with two primary variables using “2×2 factorial design”:
Scenarios:
- Peak receiving load & peak customer demand
- Average receiving load & peak customer demand
- Peak receiving load & average customer demand
- Average receiving load & average customer demand
Variables:
- Receiving load (incoming)
- Customer demand (outgoing)
This warehouse automation system included automated subsystems for handling different product sizes and volumes with different types of automation that deliver pallets and storage totes. The subsystems also used AMR and AGV technologies of different types for handling products. However, our simulation didn’t stop at the automated system, it also needed to capture the people interacting with the system when picking up the orders.
The details went further yet, including the eight upper storage levels for the dynamic picking and high volume (large pallet) picking areas, the movement of orders between multiple subsystems, a shuttle car rail-based transportation system bringing product directly to customers, and a circulating tote conveyor system for high-volume tote picking. This was a very robust model which allowed us to evaluate the system from several perspectives in search of different types of information.
Warehouse automation simulations
Using simulations, we evaluated the following:
- Inventory management control logic and order sequencing logic for dynamic, reserve, high-volume pallet, and tote picking subsystems
- Traffic and congestion issues in the automated vehicle path designs
- Pickers, pick paths, and order flow between subsystems to understand timing to complete orders
- Peaks, averages, and varying order profiles
- Automation and instantaneous utilization, and overall utilization, detailing:
- Idle time (no tasks)
- Travel time (with load)
- Travel time (empty)
- Waiting time for traffic or path to clear
- Waiting in queue to drop off or pick up a load
- Charging time
Simulation study outcome
The simulation identified the optimal number of AGVs (for the dynamic and high-volume areas), AMRs (case/tote handling robots), shuttles (for the high-density upper storage levels), and employees to maximize throughput despite varying consumer demands. The analysis was further used to highlight opportunities for improvement in the design, such as better optimization of picking slots, increasing the number of inbound pallet stands, and enhancing the planned order sequencing logic to address potential level-loading issues. This study allowed the client to test their warehouse’s automated system for flows and flaws while still in the design phase, adding confidence to an expensive and complex capital investment.
Automating your warehouse
An intralogistics system manages the internal flows of materials, packaging, finished products, and the related information throughout a facility, from dock to dock. A strategic and optimized intralogistics system reliably and continuously feeds production lines, reduces wait times, and dynamically maximizes storage.
Let’s collaborate to unlock data-driven solutions for your facility’s unique needs. Contact us today to explore how our warehouse consultants and intralogistics experts can automate and empower your next breakthrough.
