Simuraytics Software LLC home

Understand uncertainty. Make better-informed decisions.

Practical Monte Carlo simulation and cost-and-schedule risk software, developed by an experienced infrastructure risk-analysis practitioner.

Explore Our Software Meet the Founder

Developers of SimuXL and Cost and Schedule Total Risk.

Illustrative

Illustrative drawing: one estimate, many simulated outcomes An abstract illustration, not output from either product. Lines fan out from a single-point estimate to many simulated outcomes. A sideways histogram on the right shows how the outcomes are distributed: most lie above the single-point estimate, with a longer tail towards higher values. Dashed lines mark the 50th and 70th percentiles. P50 P70 Single-point estimate Simulated outcomes
Each line is one simulated outcome of a single estimate, and the bars show how those outcomes are distributed. This is a drawing, not output from either product.

Our software

Two products built around the same question: when the inputs to an estimate are uncertain, how wide is the range of outcomes, and what drives it? Each product has its own website with current features, documentation, and licensing.

CASTR Cost and Schedule Total Risk

  1. Define structure
  2. Enter base estimates
  3. Identify and triage risks
  4. Simulate and respond
The four stages of a CASTR analysis

A standalone application for probabilistic project cost and schedule risk analysis, with a particular focus on highway construction and infrastructure. Its workflow follows the risk-based estimating method taught in NHI Course 134205, and its scoring tables can be adapted to other agency standards.

What it does

  • Takes a project from its structure and base estimate through risk identification, triage scoring, and a risk register.
  • Runs Monte Carlo simulation of cost and schedule together, with seed control for reproducible runs.
  • Sets contingency at a chosen budget percentile and shows what drives it with tornado and tail-driver analysis.
  • Compares results before and after planned risk responses, so the value of a response can be weighed against its cost.
Best suited for
Estimators, project managers, and risk analysts preparing cost and schedule risk assessments for highway and other infrastructure projects, including workshop-based risk reviews.
Platform
Standalone Windows application with a local browser-based interface. It runs on your computer, not as a cloud service.
Explore CASTR costandscheduletotalrisk.com

SimuXL Monte Carlo simulation for Excel

=SXL.Triangular(8, 10, 14)
A cell that held a fixed 10, rewritten as a range from 8 to 14 with 10 most likely

A Monte Carlo simulation add-in for desktop Microsoft Excel on Windows. It lets you represent uncertain assumptions with probability distributions, simulate a spreadsheet model you already have, and review the results through charts, sensitivity analysis, and reports.

What it does

  • Enters each uncertain input as an ordinary worksheet formula, leaving the model’s existing formulas and lookups as they are.
  • Fits a distribution to past data or to an expert’s percentiles when that is what you have.
  • Shows each output’s range as a histogram and cumulative curve, with tornado, impact, and tail-driver views of which inputs matter.
  • Reproduces a run from its seed and writes HTML and Word reports that can be shared with reviewers.
Best suited for
Engineers, estimators, and analysts who already maintain a cost, schedule, or engineering model in Excel and want to see the range of results it can produce.
Platform
Desktop Microsoft Excel on Windows, 32-bit or 64-bit. Not for Excel for Mac or Excel on the web.
Explore SimuXL simuxl.com

Our approach

The two products work in different places and offer different amounts of structure. The habits behind them are the same, and they follow the order an analysis does.

  1. Represent uncertain assumptions explicitly

    Write an uncertain quantity, rate, duration, or risk as a range with a shape, instead of a single number that hides how much is unknown.

  2. Examine a range of possible outcomes

    Simulate the model many times and read the whole distribution of results, not only the most likely value.

  3. Identify influential assumptions and risks

    Find which inputs and risks move the result most, so attention and mitigation go where they make a difference.

  4. Communicate results clearly

    Present percentiles, charts, and the assumptions behind them in a form that reviewers and decision-makers can follow and check.

Simulation results depend on the model, assumptions, and input data. They support professional judgment; they do not replace it.

How each idea is carried out differs between CASTR and SimuXL. Each product’s website describes the analyses it provides.

About

Simuraytics Software LLC develops specialized software grounded in practical cost-and-schedule risk-analysis experience.

Michael Ray Smith

President & Sole Owner

Michael Ray Smith brings more than three decades of experience in highway construction cost and schedule risk analysis. He served with the Federal Highway Administration from June 1991 through December 2023, specializing in cost and schedule risk analysis for major highway construction projects.

Following his federal career, he developed software to make practical probabilistic analysis more accessible to project teams and spreadsheet users. His software combines estimating experience with probabilistic methods to help professionals understand uncertainty and make better-informed decisions.

Role
President & Sole Owner, Simuraytics Software LLC
Federal service
Federal Highway Administration, June 1991 to December 2023
Specialty
Cost and schedule risk analysis for major highway construction projects
Software
CASTR (Cost and Schedule Total Risk) and SimuXL

Contact

For questions about Simuraytics Software LLC, or about CASTR and SimuXL, email Michael Ray Smith directly.

Email

michaelsmith935@gmail.com

Current product details, documentation, and licensing are on each product’s website: