Challenge
Symbotic is a warehouse automation solutions provider. Its systems are based on mobile robots that can travel freely throughout a dense storage structure, accessing products in all locations and handling them at a very high throughput rate. The main advantages of the Symbotic System are its ability to operate in three dimensions, and their sequencing and palletizing algorithms that build stable, store-friendly pallets at maximum throughput.
The company needed a tool to help their customers learn the impact of warehouse reorganization and compare capital investments against expected operational savings before the actual introduction of automation systems. This tool had to be easily adjusted to the case of each specific client.
Symbotic specialists decided to use AnyLogic simulation software for this purpose because it could precisely estimate costs and visualize processes inside warehouses in 3D, as well as create models that could be easily reconfigured for multiple projects.
Solution
The models that Symbotic engineers created for the company’s clients simulated the environment and operations in their warehouses with a high level of detail. More specifically, this included:
- Scheduling and assignment of dock doors, product flow between the dock doors and several different warehouse locations on both inbound and outbound.
- Tracking and combining order-specific product flows from different streams on the outbound.
- Operations of labor and resources like loaders, unloaders, forklift trucks, de-palletizing and palletizing cells, all simulated as agents.
Each agent type had its own properties, like speed, reliability, operation times for equipment, dimensions, cases per layer, and layers per pallet for each SKU. The input data was taken from real life information.
It was especially important for the modelers to simulate various interactions between the automation system and human operators. This included receiving incoming deliveries, replenishing stock, both automated and non-automated parts of the warehouse fulfilling customer orders in an optimized sequence, and combining them at the dock-doors in the exact manner it would happen in the projected system. Models also took into account system reaction in case of equipment breakdowns, shift schedules and lunch-breaks for the human operators. The models featured warehouse 3D animation and graphical display of key metrics to provide strong presentation instruments for salespeople and allow the clients to see their future reorganized warehouses in action.
Results
The models were tested on the historic order data from each client, usually for a six month period. To compare warehouse operations, with and without the automation solutions introduced, Symbotic engineers gathered the following statistics in the model:
- Throughput capacity (cases per hour handled)
- Number of human operators required and associated costs
- Number of warehouse resources required (e.g. dock doors) and their utilization
- Time needed to fulfill daily outbound shipment orders, especially during the peak periods
These outputs were used by the clients to evaluate warehouse design alternatives and justify capital investments.
AnyLogic allowed Symbotic to design their simulation models in a way that made it possible to easily change warehouse layout, operating procedures, SKU properties, etc., so that model elements could be reused in multiple projects with relatively small effort. Also, 3D animation allowed the company to utilize these simulations as a powerful selling tool.
Project presentation by Dr. Larry M. Sweet, CTO at Symbotic LLC:
