A version of this blog first appeared as “Playing in a better sandbox” in Design Quarterly, Issue 29.
Discrete-event simulation, or DES, helps teams test complex building and operations plans before they commit to them.
A new factory, transit facility, or logistics hub can look flawless on paper. But the real test comes later. How will it perform when people, vehicles, equipment, and schedules all interact? What happens when queues, delays, breakdowns, and peak demand enter the picture?
Owners and operators want to know that a facility will work well, even when conditions are not perfect. DES gives teams a way to test future scenarios before making large capital investments.
It’s like creating a virtual sandbox. In it, designers and operators can compare options, test assumptions, and see how different choices affect operations and productivity.
In a competitive industrial market, better information can lead to better decisions. DES helps teams to model complex operations in a clear, visual way. It can reveal issues that static drawings, spreadsheets, and fixed calculations may miss.
DES creates a safe, low-risk virtual environment. It helps designers study complex systems and see how changes affect performance and efficiency.
" }Discrete-event simulation (DES) helps teams test complex building and operations plans. It is especially valuable for factories, transit facilities, and logistics hubs. DES creates a safe, low-risk virtual environment to run scenarios.
What is direct-event simulation?
DES is a way to model how a system changes over time. It tracks events such as arrivals, departures, delays, and operational decisions. It allows designers to model complex interactions between people, automation, inventory, vehicles, and buildings. And then we can observe the results.
Static models, such as spreadsheets and fixed calculations, assume predictable flows and stable conditions. DES is different. It accounts for variation and uncertainty. It looks at conflicts that happen when systems interact.
DES models how a system changes over time through a sequence of events. Each event changes the system’s state. The simulation tracks those changes to show what happens next. Unlike continuous simulations, it skips over periods when nothing changes.
DES is useful because it lets us quickly test many scenarios. What would happen if we added more machines or fewer docking stations? What about different layouts or schedules? DES can model unexpected events and randomness so we can prepare for challenging conditions as well as ideal ones.
Like any digital model, the better the input, the better the output. DES is best when we create a detailed model from high-quality data. DES can share results as data. Then, we can present the DES outputs as visuals, animations, and dashboards that project teams and clients can quickly grasp.
How does DES work?
We use dedicated software and a five-step process to develop the simulation model. Here are the steps:
- Define the model scope
- Develop and validate the model
- Define the solutions
- Run the scenarios
- Analyze the results
What are the benefits of DES?
- It allows us to design, analyze, and experiment with real-world scenarios. But we do it within a virtual environment.
- We can visualize concepts and proposed changes before they are applied.
We developed a DES model to compare alternative site layout options for a large distribution facility. We modeled vehicle arrivals, unloading operations, trailer staging, shunting movements, site circulation, and dock utilization.
Why does DES matter?
- Risk-free virtual experimentation: Teams can test new shift patterns, equipment layouts, and automation plans before making changes in the real world. This helps avoid costly mistakes.
- Data-driven decision-making: DES shows how systems perform under real operating conditions. Teams can compare options and make decisions based on a data-driven model.
- Life-cycle versatility: DES can support projects from early planning stages through to daily operations. It works for both new and existing facilities.
- Efficiency and cost savings: DES can find bottlenecks, test system limits, and improve how resources are used. This can boost productivity and reduce waste.
- Engagement with decision-makers: Often, DES models are shown in 3D. That helps owners, operators, and designers understand how a system works and make decisions faster.
What does discrete-event simulation have to do with design? Where does DES fit in during the design process?
DES complements design with useful intelligence. And it helps forecast outcomes. It’s a decision-support tool, not just an engineering exercise.
On new facility designs, DES adds value during predesign and early design phases. This is when insights from the simulation can drive the form, spatial configuration, and layout of the facility.
In predesign, DES can help us test basic planning assumptions.
- How many people are needed?
- How much work can the facility handle?
- Which spaces need to be near each other?
It can be used in early design phases to compare layout options and operational strategies before designs are locked in. And we can also use it on existing buildings to evaluate approaches to retrofit and modernize. We model existing conditions to establish a baseline. Then, we test future-state upgrades and changes in operations.
We can integrate DES into ongoing design efforts when a question or risk emerges. Or we can proactively include it as a core component of the project, linking future operations to current decisions as the project progresses.
" }Supporting laboratory operations at a science facility, we modeled the processing, cleaning, and sterilizing system for processing used animal cages coming from offsite. We modeled unloading, queuing, material flows, staff work breaks, sterilizing time, and energy use among other inputs.
What are the potential benefits of discrete-event simulation for industrial, advanced manufacturing, and transit facility development?
Early design sets the course for how a facility will work. Teams make key decisions about movement, distances, space relationships, and material handling. Those choices can affect operations for years. It is critical to get these right and inform these choices as much as we can.
DES can give owners and operators confidence around their choices before they make large capital investments. It lets the design team test solutions digitally before spending millions on equipment or infrastructure. Or before moving down the wrong design path. DES can help with risk reduction by identifying bottlenecks and other problems early. And it can show how design and programming can increase productivity.
During design, it can help us make better decisions more quickly. DES allows teams to rapidly compare multiple scenarios and outcomes of different design directions. We’re not debating assumptions; instead, we’re looking at data.
DES provides data that can be shown through dashboards, graphics, and 3D animations. These tools help teams compare options and see how design and operations decisions will influence performance.
" }DES also makes it easier to collaborate. Designers, engineers, operators, and owners can use the same model to understand how a system works. Teams can build a common understanding, working from infographics and even animated 3D video. Together, they can analyze the output and make changes in the system to improve the results.
It is a low-cost tool that can have a big impact. A small investment early in design may help avoid costly redesigns later. It helps teams design for movement, timing, and behavior, not just space. Better information leads to better decisions and better results.
How does discrete-event simulation play out in the real world of design?
We are already using DES in a variety of ways, including:
- Manufacturing and advanced automation: When we model manufacturing systems, it helps us understand how people, forklifts, automated guided vehicles (AGVs), and machines interact. We have tested the number of machines or AGVs required in a factory, speed, loading/unloading times, and their impact on throughput and downtime. We have helped clients to evaluate automation investments before they put it into use.
- Battery electric bus charging and transit operations: We are using DES to simulate electric bus charging schedules and infrastructure. We can model complex, dynamic conditions, such as shared charging times, arrival times, and battery condition. This helps us and our transit collaborator make informed decisions. We can consider charger quantities, site electrical servicing sizing and timing, fleet procurement, and revenue service planning.
We used DES during functional programming for a new transit operations and maintenance facility in Canada. Our simulation tested the number of wash racks needed, fueling and cleaning sequences, overnight versus daytime processing of buses, onsite queueing, and other options. We were able to rule out some options that looked good on paper but would underperform in real-world conditions.
- Logistics yards, warehouses, and loading docks: Automation powers many of the processes in today’s logistics facilities. Using DES, we have modeled truck arrivals and departures, loading dock strategies, automated storage and retrieval systems—or ASRS—and other elements for these facilities. With dashboards and visual outputs, we can compare multiple operational and infrastructure scenarios. This allowed operators to toggle between design options and see real-time impacts.
- People movement within complex facilities: DES isn’t just for buildings, trucks, autonomous vehicles, and conveyor belts. We can and have applied it to the flow of people in and out of buildings. We recently applied it to human flows in large, advanced manufacturing facilities, including clean-room manufacturing environments. Think of thousands of employees arriving, going through security, and putting on personal protective equipment before starting work. At the same time, the previous shift is doing something similar as they leave. We modeled the impact of shift changes with thousands of employees crossing paths in locker rooms, corridors, turnstiles, and queues. We’ve used the tool to help teams validate space needs and reduce the risk of congestion in high-stakes operations on day one.
We developed this DES model to visualize the movement of more than 2,000 employees during shift changes at a large industrial facility.
Designing industrial buildings for reality
Buildings and operations change over time, and design should account for that. DES helps connect operations, infrastructure, and facility design. By showing how a system may perform before it is built, DES helps teams make better decisions.
For industrial companies managing operations and maintenance facilities, manufacturing plants, and logistics hubs, DES is more than a technical tool. It helps teams plan and base decisions on evidence.
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