SpiceLogic Rational Will ®

Use decision trees, AHP, Markov decision processes and Bayesian inference in one Windows suite. Quantify risk and explain your choices.

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Some decisions deserve more than a gut call: a career, an acquisition, a clinical strategy.

Rational Will brings every serious method to one desk, so your reasoning stands up.

01

Intuitive User Experience

The suite also includes utility functions and multi-criteria analysis. Model decisions, quantify risk using certainty equivalents and sensitivity analysis, and present the reasoning to a board, committee or reviewer. Pay once, use forever.

The user experience of Rational Will® is intuitive enough so that you won't feel lost.
Rational Will
02

Policy path in a rich Decision Tree

Based on your attitude towards risk, get a policy from a Decision Tree and know what action to take in what situation; Always have your plan-B ready before jumping to an action.
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Decision Tree Maker
03

Cost-Effectiveness Analysis for Healthcare

We are proud of the Cost-Effectiveness Plane visualizer we developed within Rational Will for healthcare students. You can incorporate QALY or DALY as your effectiveness payoff into an action or event node. You can select the QALY or DALY formula according to your need.
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Cost-effectiveness analysis in healthcare

More features

04 Create a simple or complex Markov Chain inside a Decision Tree Model Markov Chain directly into the Decision Tree and get Cohort Simulation results.
Model Markov Chain directly into the Decision Tree and get Cohort Simulation results. Attach rewards to the Markov States and turn the chain into a Markov Decision Process. Use time-variant probabilities for a Markov chain that changes over cycles.
Markov Chain Healthcare
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05 Visualize various metrics and charts of your Markov Decision Process Have a big screen?
Have a big screen? Enjoy the array of charts and metrics generated from your Markov Decision Process.
Markov Decision Process Charts and Metrics
06 Extensive modeling of a Utility function Rational Will ® has extensive coverage on Von Neumann-Morgenstern Utility Theorem .
Rational Will® has extensive coverage on Von Neumann-Morgenstern Utility Theorem. Model your Utility function as many ways as possible using our rich visual drag and move chart editor. You can directly use the Exponential Utility Function, or Bernoulli Utility Function as well. Finally, use custom expressions if any of the built-in models won't suit your taste.
Various Utility Functions
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07 Sensitivity Analysis It is not worth trying to make everything perfect.
It is not worth trying to make everything perfect. Rather focus on and optimize the factors that matter most. Thru an exhaustive Sensitivity Analysis, see, how significantly your decision can change by changing a factor in your context. (What-If Analysis)
Sensitivity Analysis
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08 Multi-Criteria / Multi-Objective decision analysis You can set payoff for an action or an uncertain event with Multiple-criteria Utilities.
You can set payoff for an action or an uncertain event with Multiple-criteria Utilities. Rational Will® objectives can encapsulate rich information for a payoff with multiple criteria. For example, some attributes can be Boolean Type (yes/no or true/false); some of them can be a Subjective type, Number type, or Categorical. Monetary type objectives can be used to calculate Net Present Value using an interest rate.
Multi Criteria Decision Analysis
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09 Rich math expression editor for Multi-Criteria Utility Function and Monte Carlo Simulation Drag and drop criteria to the expression editor, and use a mathematical operator and built-in functions to form your custom expression.
Drag and drop criteria to the expression editor, and use a mathematical operator and built-in functions to form your custom expression. You will love this editor when you will need to perform a Monte Carlo simulation of your Random Function.
Multi Criteria Utility Function
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10 Risk Analysis Realize the risks in any action you take.
Realize the risks in any action you take. Observe a plethora of risk metric charts including Value at Risk, Entropy, Baumol's Risk measure, Domar and Musgrave Risk Index, Roy's safety first rule, Shortfall VaR, Variance, Standard Deviation, Certainty Equivalent, Risk Premium, etc.
Value At Risk
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11 Every chart can be viewed as a data grid or exported to Excel. Every chart you see in this application has a context menu that shows up with a right mouse click.
Every chart you see in this application has a context menu that shows up with a right mouse click. In that context menu, you will find the option to view the chart data as a data grid or export the data as excel. Copy the data as CSV. Copy the image into the clipboard or save it as JPG/PNG.
chart features
12 Analytic Hierarchy Process Now, Rational Will lets you model Analytic Hierarchy Process, and that extends your capabilities as a decision-maker in your organization.
Now, Rational Will lets you model Analytic Hierarchy Process, and that extends your capabilities as a decision-maker in your organization.
Analytic Hierarchy Process
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13 Bayesian Network Create a Bayesian network in a very intuitive way, and diagnose the Root cause.
Create a Bayesian network in a very intuitive way, and diagnose the Root cause.
Bayesian Network
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14 Bayesian Inference Whenever you model uncertainty, you can update your beliefs based on experimentation and observations.
Whenever you model uncertainty, you can update your beliefs based on experimentation and observations.
Bayesian Inference
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15 Model Probability Distribution as a payoff. You can directly integrate a probability distribution as a payoff in your decision tree node.
You can directly integrate a probability distribution as a payoff in your decision tree node.
Probability Distribution - Monte Carlo Simulation
16 Monte Carlo Simulation When you have a probability distribution, Monte Carlo Simulation is performed automatically without asking you anything to configure.
When you have a probability distribution, Monte Carlo Simulation is performed automatically without asking you anything to configure. Whenever you have uncertainty, the Risk Profile chart is generated for you to visualize the complete possibilities of uncertain events and realize what can go wrong. Get prepared accordingly.
Monte Carlo Simulation
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17 Incorporate your attitude The Rational Will ® computes a strategy based on your attitude.
The Rational Will® computes a strategy based on your attitude. If you acknowledge as a realist rational person, the Von Neumann-Morgenstern utility theorem - Maximize Expected Utility approach will be used. If you are a very pessimistic person who wants to avoid all kinds of risks, you can choose the LexiMin approach. If you regret opportunities, then the Minimax Regret approach is available for you. Hurwicz’s Optimism Pessimism rule is also available along with various customizations.
Decision Criteria
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18 Stochastic Dominance: (Up to the 3rd order). When you compare random variables, Stochastic Dominance measures should be considered to rank the variables.
When you compare random variables, Stochastic Dominance measures should be considered to rank the variables. Rational Will® can calculate Stochastic Dominance up to the 3rd Order. Whenever a model contains uncertainty, the stochastic dominance is calculated in the Result Panel.
Stochastic Dominance
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19 Get a detailed report in PDF and Excel What would be the use of decision analysis software if you cannot create a beautiful PDF or Excel report?
What would be the use of decision analysis software if you cannot create a beautiful PDF or Excel report?
report-PDF-excel-thumb
20 A bundle of many of our software You may notice that we offer some stand-alone decision analysis software, like Decision Tree Analyzer , Bayesian Network Software/Bayesian…
You may notice that we offer some stand-alone decision analysis software, like Decision Tree Analyzer, Bayesian Network Software/Bayesian Doctor, Analytic Hierarchy Process, etc. If you get Rational Will®, then you will get all of them into a single software, which is definitely a streamlined user experience. You won't have to get them separately anymore.

Cited in 128 peer-reviewed papers.
Used for coursework at 293 universities.

Researchers do not cite tools they cannot defend. When a method has to hold up under review, the software behind it gets scrutinized too.

Browse the research index
  • Ichlasul Amal, et al. Meningkatkan Kepatuhan Terhadap Standar Pakan Nasional: Pendekatan AHP Berbasis Pemangku Kepentingan untuk Peningkatan Kualitas Jagung di Sulawesi Selatan. Jurnal Ilmu Peternakan Halu Oleo, 2026. DOI
  • Jiyoung Shim. Exploring the Relative Importance of Reading Material Selection Factors Using AHP. Journal of the Korean Society for Information Management, 2026. DOI
  • T. G. Asresehegn, V. Valencia, S. Schulz, G. Woldewahid, G. Gebrehawariat, R. P. O. Schulte. Community responses to land degradation: Insights from land restoration bright-spot communities in the Ethiopian Highlands. Environmental Development, 2026. DOI

The three most recent entries from our research index.

University of North Carolina at Charlotte · University of Sharjah · University of manchester · Chulalongkorn University · Colorado State University · Institut Teknologi Bandung · Institut Teknologi Sepuluh Nopember · IPB UNIVERSITY · and 285 more.

Source: our student-license survey, 293 universities and counting.

Terms that have become rare.

01

Your data never leaves your machine.

Fully offline desktop software. Your models and results never touch a server, ours or anyone's. Nothing to upload, nothing to leak.

02

You buy it once. It is yours.

A true perpetual license, sold this way since 2007. No subscription meter running while you finish the work.

03

One-to-one support from a human domain expert.

Not a chatbot, not a call center. Support is a live conversation with the engineers who build the software. One call away, on Zoom or Teams, free.

From people who had a deadline.

Alexandre Soares Sarto Alexandre Soares Sarto Student, IPT - Instituto de Pesquisas Tecnológicas Verified via LinkedIn
Helped me to finish my master's degree First of all, it is a software that has lots and good resources and documentation. This software (Rational Will) has support and it is so important, especially when someone needs to deal with something so important as a master's course.
Arthur Worlobah Student, Northcentral University
The software has a great user interface and easy to use. I will be using this software for my research in decision making in healthcare. The features of the software and its ease of use.

Stuck at 11 p.m. with a model due Friday? Talk to our engineers.

Every trial and every license includes free live 1:1 sessions on Zoom or Teams. You will talk to a real human, a domain expert who builds this software, and we will help you model your actual problem. No chatbot, no call center, no ticket queue.

Weigh it yourself. The trial is the full product: free, offline, on your machine.

Download free trial

7-day full trial

Book a live demo

Free, 1:1 with our engineers