Decisions you can defend.
Simulate before you spend.

Thirty-five years building decision applications for 300+ companies, including many Fortune 500 operators. See the proof.

▭ Artificial Intelligence
+
△ Operations Research
=

Explore the efficient frontier for your problem

Simulation, reliability statistics and AI agents for production lines and supply chains.

~1%
OEE Accuracy
13%
Energy Reduction
300+
Organizations Served
35+
Years OR Expertise
A few of the 300+ organizations we’ve built for since the early 1990s
AS FEATURED IN USA TODAY Business Insider digitaltrends
The Suite

Tools built for
hard problems

AI Agent Sandbox
Validated Production Models

Discrete rate simulation validated within 1% OEE. Find improvements your loss tree will never surface. AI agent grounded in your scenario.

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AI Agent Sandbox
SCModeling
Design. Optimize. Simulate. Prove.

Sketch a supply chain on the canvas, drop optimization on it (AMOS / SCG), run discrete-event simulation against the result. 10 demos against real sample data, with engine output visible inline.

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AI Agent Sandbox · Free
QueueSim
M/M/c Queueing Simulator

Run any of four preset scenarios (single server, coffee shop, grocery checkout, call center), watch the queue form, and ask the on-page agent to interpret the result. Pairs with the public MCP for use inside Claude.

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AI Agent Sandbox
Distribution Fitting

8 distribution types, Quick Start solver, interrupt designer. Turn historian data into simulation-ready parameters. AI agent for theory + interpretation.

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Supply Chain
Greenfield Analysis
Network Design & Optimization

Candidate facility locations from your own customer and demand data, in minutes, not months.

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AI Agent Sandbox
QSimHealth
ED staffing decisions, modeled before you commit.

Run your emergency department's numbers, compare staffing scenarios, see the wait-time and cost tradeoff. Developed in conjunction with the University of Tennessee Physician Executive MBA program.

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Live Sandbox · Free
Decoupling
Simulator
Custom Web App

Simulate decoupling strategies for flaked product lines in seconds, not months. Test off-ramp dryers, tote storage, and on-ramp reconstitution modules against real production data — validate improvement ideas before you implement.

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Process Intelligence
Real-Time Operator Guidance

Dynamic mass-energy balance for thermal processing. Expert coaching to operators in real-time. 13% energy reduction, 0 safety incidents.

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Industrial IoT
Adaptive Edge
Edge Data Acquisition

Drop a $500 box on the plant floor, plug in Ethernet to the PLC, power on. Time-series data with dashboards — no cloud, no IT department.

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AI Agent Sandbox · Free
DiscreteRate
Discrete Rate Simulation Paradigm

Three demos (Fast-Slow Drain, Hamburger Duo, Valdez Tanker) of the rate-based paradigm Andrew Siprelle invented in 1990. Teaching agent quotes engine output verbatim. Companion textbook in progress.

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Use ChiAha from your AI chat

Run ChiAha simulations
inside Claude, ChatGPT, Cursor

Every ChiAha tool is also a public Model Context Protocol server, registered in the official directory. Ask Claude a staffing question, an OEE question, a queue question — it calls the real simulation engine and answers with verbatim numbers. No login, no API key on the public surface; you pay the LLM provider through your own account.

com.queuesim/public
QueueSim
M/M/c queueing sims, Erlang-C validation, inverse staffing for any line.
queuesim.com/mcp/v1
com.qsimhealth/public
QSimHealth
ED staffing simulator with MD-only demo; talk to a healthcare-fluent agent.
qsimhealth.com/mcp/v1
com.reliasim/public
ReliaSim
Production-line DES with the bottling-line paired model + Buffer Tradeoff.
reliasim.com/mcp
com.reliastats/public
ReliaStats
Reliability theory + closed-form math: Weibull shapes, MTTF/MTBF, availability, RBD system reliability, distribution recommendations.
reliastats.com/mcp/v1
com.scmodeling/public
SCModeling
Supply-chain optimization + sc-sim engine via 11 tools (engine delegate + AMOS / Greenfield catalogs).
scmodeling.com/mcp
com.discreterate/public
DiscreteRate
Teaching agent for the DRS paradigm: FSD, Hamburger, Valdez. Engine-truth verbatim.
discreterate.com/mcp/v1
Install one from Claude.ai Connectors, Claude Desktop, or Cursor — paste the URL, no key required. Each tool runs the real engine and returns numbers you can quote verbatim. What is MCP?
Our Approach

Built from
first principles

01 —

Math you can check

Every tool is built on queuing theory and reliability statistics, and the methods are published.

02 —

AI reads the model

AI reads the loss tree and points at the Labeler. Simulation reveals the real story: 120 one-minute micro-stops on the Filler cascading through the line. Every ChiAha tool ships with a chat agent and a public MCP — the analytics are reachable from your AI conversation as well as our apps. See how →

03 —

One field at a time

Each tool is built for one kind of problem, such as reliability on high-speed lines, patient flow in clinics or thermal processing, and starts from that field’s own data and terms.

04 —

Starts from a decision

A model begins with a question someone has to answer, such as which failure mode to fix first, how big a buffer should be, or where a distribution center should go.

In Their Own Words

Named customers.
specific outcomes.

"We leveraged the model to recommend solutions that saved $21.7M in inventory carrying costs and reduced transit time by 19%."
— Mike Keller, Network Analyst & Engineer, Union Pacific Railroad
"Instead of taking a snapshot, this is more like a video. Your ability to actually see the activity in action while the supply chain is running lets you understand impacts much better."
— Mike Geddis, Director of Engineering, General Mills
"The team went above and beyond the project scope, proactively brainstorming ways to make our project better."
— J. Adam Traina, Director of Operations Research, Symbotic
Research & Publications

35 years of
peer-reviewed work

Read how Andrew Siprelle invented Discrete Rate Simulation in 1990 →

Our Books

Books from our team
Eight Principles of Effective Problem Solving
Eight Principles of Effective Problem Solving
David Parsons
Educating Problem Solvers
Educating Problem Solvers
David Parsons
AI: Thinking Without Understanding
AI: Thinking Without Understanding
David Parsons
Machine Learning Projects for .NET Developers
ML Projects for .NET Developers
Mathias Brandewinder
Infinity Within His Grasp
Infinity Within His Grasp
David Parsons
Gravity
Gravity: How to Weigh the Sun
David Parsons
COVID-19: Anatomy of a Pandemic
COVID-19: Anatomy of a Pandemic
David Parsons

Peer-Reviewed Papers & Conference Proceedings

Peer-reviewed and conference work published by the Simulation Dynamics and ChiAha team.

2010 Safety Stock Savings from Flexible Ordering: A Simulation StudyDavid J. Parsons, Simulation Dynamics. 2004 Impact of Production Run Length on Supply Chain PerformanceDavid J. Parsons, Robin J. Clark, Kevin L. Payette, Simulation Dynamics. WSC 2004. 2003 Benefits of Using a Supply Chain Simulation Tool to Study Inventory AllocationAndrew J. Siprelle, David J. Parsons, Robin J. Clark, Simulation Dynamics. WSC 2003. 2003 Initializing a Distribution Supply Chain Simulation with Live DataMalay A. Dalal, Union Pacific Railroad; Henry Bell, Mike Denzien, Simulation Dynamics; Michael P. Keller, Insight Network Logistics. WSC 2003. 2002 Non-Item Based Discrete Event Simulation ToolsRichard A. Phelps, David J. Parsons, Andrew J. Siprelle, Simulation Dynamics. WSC 2002. 2002 Simulation of Transuranic Waste Processing, Transportation, and Disposal OperationsSue Downes, Sandia National Laboratories; David J. Parsons, Amber D. Clay, Simulation Dynamics. Waste Management Symposium 2002. 2001 SDI Supply Chain Builder: Simulation from Atoms to the EnterpriseRichard A. Phelps, David J. Parsons, Andrew J. Siprelle, Simulation Dynamics. WSC 2001. 2001 Production Scheduling Validity in High Level Supply Chain ModelsDavid J. Parsons, Richard A. Phelps, Simulation Dynamics. WSC 2001. 2001 Performance Assessment of Supply Chain SimulationsDavid J. Parsons, Andrew J. Siprelle, Richard A. Phelps, Simulation Dynamics. 2001 Combined Use of Optimization and Simulation Technologies to Design an Optimal Logistics NetworkGlenn W. Wegryn, Associate Director, Global Analytics, The Procter & Gamble Company; Andrew J. Siprelle, Simulation Dynamics. Council of Logistics Management, 2001. 2000 The SDI Industry Product Suite: Simulation from the Production Line to the Supply ChainRichard A. Phelps, David J. Parsons, Andrew J. Siprelle, Simulation Dynamics. WSC 2000. 2000 A Supply Chain Case Study of a Food Manufacturing MergerDavid J. Parsons, Andrew J. Siprelle, Simulation Dynamics. WSC 2000. 2000 Simulation of Waste Processing, Transportation, and Disposal OperationsJanis Trone, Angela Guerin, Sandia National Laboratories; Amber D. Clay, Simulation Dynamics. WSC 2000. 1999 SDI Industry Pro: Simulation for Enterprise-Wide Problem SolvingAndrew J. Siprelle, David J. Parsons, Richard A. Phelps, Simulation Dynamics. WSC 1999. 1999 Tactical Logistics and Distribution Systems (TLoaDS) SimulationDavid J. Parsons, L. C. Krause, Simulation Dynamics. WSC 1999. 1998 SDI Industry: An Extend-Based Tool for Continuous and High-Speed ManufacturingAndrew J. Siprelle, Richard A. Phelps, M. Michelle Barnes, Simulation Dynamics. WSC 1998. 1998 Capacity Planning Simulation of an Olive Processing PlantM. Michelle Barnes, Richard A. Phelps, Simulation Dynamics; Robert Rugeroni, Lindsay Olive Company. Manuscript, 1998.
1998 Modeling Offshore Pipelaying Operations Using SimulationD. C. Angelides; Richard A. Phelps, Simulation Dynamics; W. T. Himel. International Journal of Offshore and Polar Engineering, Vol. 8, No. 3, September 1998.
1997 Simulation of Bulk Flow and High Speed OperationsAndrew J. Siprelle, Richard A. Phelps, Simulation Dynamics. WSC 1997. 1997 Using a Making/Packing Simulator to Aid in Process ReengineeringDavid J. Parsons, Andrew J. Siprelle, Simulation Dynamics. Powder & Bulk Solids Conference, 1997. 1997 Solving Problems in Processing & Packaging Using SimulatorsAndrew J. Siprelle, Simulation Dynamics. Powder & Bulk Solids Conference, 1997. 1997 Integrating Manufacturing and Supply Chain SimulationSimulation Dynamics, February 1997. Multi-level modeling across SDI Manufacturing and SDI Supply Chain. 1997 Modeling a Microbrewing Facility Using Discrete Event SimulationAndrew J. Siprelle, Simulation Dynamics. Presentation paper, c.1997. 1995 Modeling a Bulk Manufacturing System Using ExtendAndrew J. Siprelle, David J. Parsons, Simulation Dynamics. WSC 1995. Soap Manufacturer Saves Over $4 Million with SDI Industry ProSimulation Dynamics case study.

Press & Trade Coverage

Independent trade press and talks covering our work.

2025 How Data-Based Simulations Find the Fastest Wins and Best Options for OptimizationChiAha presentation, 2025. 2004 Simulation Dynamics Takes the Guess-Work Out of SCMIndustrial Engineer advertorial, March 2004. Roland Fortner, Malay Dalal and Mike Keller of Insight Network Logistics, a Union Pacific subsidiary. 2004 Supply Chain Performance Enhanced Using SimulationValerie Hendrix and Paula Solomon, Simulation Dynamics. BusinessWeek project profile, 2004. 2003 Virtual Engineering’s New FrontierKevin T. Higgins, Senior Editor, Food Engineering, 22 March 2003. Andrew J. Siprelle on flow architecture; Robert Rugeroni, Bell-Carter Foods; Malcolm Beaverstock, General Mills. 2001 Simulation Dynamics Puts Power into SCMIIE Solutions, June 2001. Featuring Mike Geddis, Director of Engineering, General Mills. Lindsay Olive Company Thrives on SimulationFood Online case study. Robert Rugeroni, Lindsay Olive Company, on the SDI Industry capacity model.

Customer & Partner Publications

Peer-reviewed papers written by customers and partners about work carried out with our tools. Authored by them, not by us.

2020 High Accuracy Discrete Rate and Reliability Modeling to Drive Improvement of Plant OEE and ThroughputLawrence B. Fischel, Clorox Services Company; Thomas J. Lange, Technology, Optimization, and Management. WSC 2020. 2007 A Supply Chain Paradigm to Model Business Processes at the Y-12 National Security ComplexReid Kress, Jack Dixon, Tom Insalaco, Richard Rinehart, Y-12 National Security Complex. WSC 2007. 2006 Database-Intensive Process Simulation at the Y-12 National Security ComplexReid Kress, Karen Bills, Jack Dixon, Richard Rinehart, BWXT Y-12. WSC 2006. 2003 Discrete-Event Model of Mining Operations at the Waste Isolation Pilot PlantReid Kress, University of Tennessee; Carla Mewhinney, Sue Downes, Sandia National Laboratories. Waste Management Symposium 2003. Built on Extend with SDI Industry. 2001 T.LoaDS Abbreviated Systems ArchitectureBob Hamber, Naval Facilities Engineering Service Center. WSC 2001.

Related Papers

Discrete-rate and mesoscopic simulation work by researchers outside our team, listed because it builds on, compares against, or extends the methods above.

2020 Mesoscopic Discrete-Rate-Based Simulation Models for Production and Logistics Planning 2017 Application of Discrete-Rate-Based Simulation Models for Production and Logistics 2017 Comparison of a Microscopic Discrete-Rate and a Mesoscopic Discrete-Rate Simulation Model 2016 Comparison of Discrete Rate Modeling and Discrete Event Simulation 2014 A Global Approach for Discrete Rate Simulation 2013 Simulation of Mixed Discrete and Continuous Systems: an Iron Ore Example 2012 Mesoscopic Supply Chain Simulation 2011 A Mesoscopic Approach to Modeling and Simulation of Logistics Processes 2010 Advanced Logistics Analysis Capabilities Environment (BALANCE)Steven E. Saylor, James K. Dailey, Boeing Research & Technology, The Boeing Company. WSC 2010. Builds on the non-item based approach, citing Phelps, Parsons and Siprelle (2002). 2009 ExtendSim Advanced Technology: Discrete Rate Simulation 2008 Discrete Rate Simulation Using Linear Programming 2003 Simulation of the Grape Reception at a WineryAndrés Auger, Juan-Carlos Ferrer, Sergio Maturana, Jorge Vera, Pontificia Universidad Católica de Chile. Cites the Barnes, Phelps and Rugeroni olive processing report. 2000 The Extend Simulation EnvironmentDavid Krahl, Imagine That, Inc. WSC 2000. Presents an SDI Industry model as a worked example.
Services

From raw data to prediction

ChiAha provides services supporting teams in adopting a proven, scientific approach for faster, better operational decisions. Using your data, our simulation techniques draw from 35 years of manufacturing modeling expertise.

OEE & Throughput Simulation

Capacity modeling, bottleneck identification, and what-if analysis.

TOC, Lean & Systems Thinking

Practical application of constraint theory and lean principles.

Verify & Validate

Check the model against your historian data before trusting its predictions.

Practical AI

Convert production questions into data-driven decisions.

Feasibility & Sensitivity Analysis

Model-based configuration testing and risk assessment.

Discrete Rate Modeling

Models line flow as rates that change when machines stop and start, so a year of production runs in under a second.

About

35 years of building models
that work.

ChiAha was created with consulting partners from Technology Optimization & Management, representing 35 years of intensive model-building for diverse industries.

Founder
Andrew Siprelle

Educator, consultant, and simulation tool developer. Creator of Discrete Rate Simulation (1990). Most advanced analytics never reach the people who need them. Thirty-five years spent making AI, operations research, and high-power computing actually improve systems — not just fill white papers. ChiAha puts those tools in your hand.

Product Manager / Designer
Amber Siprelle

Product lead across the ChiAha tool family. Shapes the sales, marketing, and user experience surface for ReliaSim, ReliaStats, DiscreteRate, and the broader ChiAha product suite.

Doctors of Reliability
Tom Lange
36-year retired R&D & Engineering Director, P&G

Modeling & simulation, reliability engineering, high-performance computing.

Peter Au-Yeung
35-year retired Senior Reliability Engineer, P&G

Reliability engineering, data analysis, modeling & simulation.

Jeff Holland
32-year retired Global Baby Care Director of Reliability Engineering, P&G

Reliability management, maintenance engineering.

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