Modeling and Simulation

Simulation modeling is a powerful tool that can be used to accurately model and analyze existing or future systems. Leveraging simulation allows organizations to evaluate the effects of changing system parameters (facility layout, workforce scheduling, product flow, operational concepts, etc.) on measures of performance without interrupting the operation of the current system or building a proposed system.

PAI is a proven industry leader in developing valid discrete-event, continuous, and object-oriented simulation models of real world systems to provide process and efficiency improvements. Our simulation consulting services include: 

  • Development of Simulation-Based Decision Support Systems
  • Evaluation and Selection of Appropriate Simulation Software
  • Application of Rigorous Statistical Analysis and Validation Methodologies 

Whether it is analyzing space launch vehicles processing flow, patient flow in a health facility, or product flow within a manufacturing plant - you can use PAI's simulation expertise to improve your process or service.  Apply our insights and years of experience in simulation modeling to your next project and earn cost savings and increased efficiency.


Example Projects



PAI has developed the only simulation environment available to NASA to aid in the evaluation of future space vehicle designs. GEM-FLO (the Generic Simulation Environment for Modeling Future Space Launch Operations) was developed with funding from NASA, to accurately predict processing turnaround times and other effectiveness criteria to support key business and program decision-making.

GEM-FLO is a state-of-the-art, generic, discrete event simulation platform designed to accept any expendable or reusable launch vehicle design characteristics and operational inputs to automatically generate a simulation model of the system under study. Once executed, the simulation model outputs values for performance metrics such as flight rate, vehicle turnaround time, and facility utilization, thus, enabling users to fairly assess multiple future vehicle designs early in the design phase using a common platform.  

GEM-FLO has been widely adopted by various NASA programs including the Shuttle, the Orbital Space Plane (OSP), and Crew Exploration Vehicle (CEV) Programs. It has also been used by NASA contractors such as Lockheed Martin.



In-House Developed Capability

At PAI, we understand the key challenges facing today's airport passenger terminals include:

  • Accommodating increased passenger demand within capital resource constraints
  • Increasing passenger expectations, service and satisfaction while experiencing lower per passenger revenue
  • Making the business case for technology insertion for improved processing of passengers and their baggage
  • Accommodating existing and emergent regulatory and security requirements
  • Optimizing flows associated with arriving and departing ground transportation facilities.

To assist airport planners and operators, PAI has developed AirSim, a generic airport simulation modeling and analysis tool, that provides valuable insight to Airport Authorities, TSA, Airlines, and the FAA, in analyzing the current state of airport's key processing elements and their performance. The tool provides a scalable and customizable environment that allows decision makers to perform capacity analysis studies and determine operational areas that are likely to impede additional passenger processing. AirSim is based on a discrete event simulation engine and accurately captures the dynamics nature and variability in airport processing elements.

Common use cases for AirSim are:

  • To analyze the current state of the airport, e.g. capacity utilization, queue length, wait times in queues, space occupied in queues, baggage claim status, etc.
  • To determine the various bottlenecks that impede the processing of additional passengers.
  • To analyze airport operations and schedules, redesign ticketing and baggage scanning space, analyze and optimize security checkpoints, and optimize usage of existing and new facilities.
  • To assess investment decisions such as the need to build a new terminal complex or install new security check machines.
  • To Conduct What-if analysis, e.g. what if the MAP (million annual passenger) increased by certain %; what if the number of check points increased by one; what if airline X installs more e-ticketing machines.

PAI has successfully used AirSim to develop a comprehensive capacity-planning tool for the Orlando International Airport. The tool is used to determine how to make efficient use of available airport resources to improve passenger flow through the airport.


Exploration Launch and Landing Analysis


In this project, PAI delivered to NASA Kennedy Space Center (KSC) a discrete event simulation model and analysis capability related to ground processing operations of space vehicles for "Project Constellation". The primary use of this analysis tool was to support the initial concept development and strategic plan, forming the basis for the preferred system design when taking into account the overall resource and physical constraints associated with operations at KSC. This project was awarded to PAI as a result of a competitive BAA to support the Presidents 'Vision for Exploration'.

Orlando International Airport Terminal Flow Optimization

Greater Orlando Airport Authority (GOAA)

A major challenge for airport planners is predicting and preventing the various bottlenecks that impede passenger flow through the terminal. Emerging technologies, security regulations, and air travel patterns are making airport operations more complex and dynamic every day.  Airport planners must adapt and leverage state of the art technologies to help them achieve their performance and customer service goals. 

In order to help the Orlando International Airport to conquer this challenge, PAI used Airsim to customize a simulation-based decision support tool for analysis of airport terminal enplanement and deplanement operations. This tool enables GOAA planners to analyze airport operations and schedules, redesign ticketing and baggage scanning spaces, analyze and optimize security check points, and optimize usage of existing and new facilities.

Physics-Based Modeling and Simulation of Theme Park Rides

Universal Studios

PAI developed a physics-based simulation of ride systems to assess the impact of the timing of individual mechanisms (sensors, breaks, etc.) on capacity.  Our team developed a digital model of the ride to simulate its physical behavior and work in a loop with the physical controllers through an emulator integration. The resulting tool and analysis led to streamlined operations and drastic reduction in guest wait time.

Disney’s Magical Express (DME) Process Reengineering

Walt Disney World

In this project, PAI developed a simulation based decision support tool that captures Disney Magical Express's end-to-end process for guests as well as their baggage. The main objective was to identify and quantify the gap between guests' arrival to the resorts and their baggage arrival. The goal was to identify opportunities to eliminate/narrow these gaps. The resulting tool and analysis assisted Disney to significantly reduce the time to deliver the baggage to the guests at the resorts, hence improving service levels.