what are Fuzzy Dematel Steps?

1- Define Criteria 2- Establish Relations 3- Calculate Scores 4- Find Influence 5- Analyze Results 6- Make Decisions

What is Fuzzy Dematel software?

Fuzzy DEMATEL software offers a user-friendly interface, easy Excel data import via copy & paste, comprehensive help, and a free demo version. With no installation required, you can edit each project effortlessly, making it an ideal tool for efficient and accurate decision-making and criteria prioritization.

Fuzzy Dematel

A method for analyzing the causal relationships and degree of influence among criteria, in situations where judgments or data are not certain and are expressed using fuzzy numbers.

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Fuzzy DEMATEL cause and effect network diagram

Understanding Fuzzy DEMATEL

What is Fuzzy DEMATEL?

Fuzzy DEMATEL (Decision Making Trial and Evaluation Laboratory) is a multi-criteria decision-making method used to identify and visualize the cause-and-effect relationships among a set of criteria. Unlike the classical DEMATEL method, which relies on crisp numerical judgments, Fuzzy DEMATEL incorporates fuzzy numbers to handle the uncertainty and vagueness that often exist in expert opinions.

When to Use Fuzzy DEMATEL

This makes it especially useful when decision-makers cannot express their judgments with exact numbers — for example, when comparing the influence of risk factors in a supply chain, evaluating barriers to sustainability, or analyzing interdependent criteria in strategic planning. By converting linguistic terms like “high influence” or “moderate impact” into triangular fuzzy numbers, the method produces a more realistic and reliable causal diagram than its classical counterpart.

Why Choose Fuzzy DEMATEL

Choose Fuzzy DEMATEL over classical DEMATEL whenever your experts express judgments in vague or linguistic terms rather than precise numbers — this is common in early-stage strategic decisions or when consensus among evaluators is low.

Where Fuzzy DEMATEL Is Applied

Fuzzy DEMATEL is widely applied in engineering, supply chain management, healthcare, and environmental studies, where relationships between criteria are complex and judgments are inherently subjective.

How to Calculate Fuzzy DEMATEL — Step by Step

Step 1: Define the Criteria

List all the criteria or factors you want to analyze for cause-and-effect relationships.

Step 2: Collect Expert Judgments

Ask experts to rate the influence of each criterion on the others using linguistic terms (e.g., “no influence,” “low,” “medium,” “high,” “very high”).

Step 3: Convert to Fuzzy Numbers

Translate each linguistic term into a triangular fuzzy number (a lower, middle, and upper value) to capture the uncertainty in expert judgments.

Step 4: Build the Fuzzy Direct-Relation Matrix

Combine all expert responses into a single matrix showing the fuzzy relationship between every pair of criteria.

Step 5: Defuzzify and Normalize

Convert the fuzzy values into crisp (single) numbers, then normalize the matrix so all values fall within a consistent scale.

Step 6: Calculate the Total-Relation Matrix

Use matrix algebra to compute how much each criterion influences — and is influenced by — the entire system, not just its direct neighbors.

Step 7: Determine Cause-and-Effect Groups

Calculate two key values for each criterion: (D+R), showing overall importance, and (D−R), showing whether it’s a net “cause” or “effect” factor.

Step 8: Visualize the Causal Diagram

Plot the results on a cause-and-effect diagram to clearly see which criteria drive the system and which ones are driven by others.

See It in Action

Curious how Fuzzy DEMATEL works? Walk through a solved example — or skip straight to analyzing your own criteria with our free online tool.

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Advantages and Limitations of Fuzzy DEMATEL

Advantages	Limitations
✓ Handles uncertain or vague expert judgments	! Requires input from multiple experts, which can be time-consuming
✓ Reveals both direct and indirect relationships between criteria	! Defuzzification can introduce subjectivity
✓ Distinguishes “cause” factors from “effect” factors	! Results depend heavily on expert selection and consistency
✓ Produces a clear visual causal diagram	! Not designed for ranking alternatives — only for analyzing criteria relationships

How Fuzzy DEMATEL Compares to Other Methods

Fuzzy DEMATEL vs. Classical DEMATEL

Classical DEMATEL uses crisp numerical judgments, while Fuzzy DEMATEL captures uncertainty through fuzzy numbers — making it more suitable when expert opinions are vague or inconsistent.

Fuzzy DEMATEL vs. Fuzzy AHP

Fuzzy AHP is used to weight and prioritize criteria based on pairwise comparisons, while Fuzzy DEMATEL focuses on identifying cause-and-effect relationships between criteria rather than ranking them.

Fuzzy DEMATEL vs. Fuzzy ANP

Fuzzy ANP builds on network relationships between criteria and alternatives, and is often combined with Fuzzy DEMATEL results to build a more accurate network structure.