DEMATEL Decision-Making Method

DEMATEL (Decision-Making Test and Evaluation Lab) is a structured decision-making method developed by Hwang and Lapan in 1974, later enhanced with fuzzy set theory to handle human subjectivity. It evaluates the causal relationships between factors in a system by creating an influence matrix from expert judgments. Factors are categorized into 'cause factors' (drivers) and 'effect factors' (consequences). In the context of automated vehicles, it is used to evaluate the interaction between Functional Safety (ISO 26262) and Cybersecurity Management Systems (ISO/SAE 21434), ensuring that regulatory requirements are not only met but integrated logically. This methodology provides a quantitative basis for risk-adjusted decision-making, which is essential for compliance with international standards like UN R155 and R156.

Implementation typically follows four steps: 1) Define the evaluation scope and factors (e.g., threat-analysis, data-protection, supply-chain-integrity); 2) Collect expert ratings using fuzzy linguistic scales; 3) Calculate the causal matrix to determine the net influence of each factor; 4) Prioritize factors for mitigation based on their causal ranking. For example, a Taiwanese automotive electronics manufacturer could use DEMATEL to identify that 'threat-analysis-process' is a primary cause factor, while 'system-uptime' is a result factor. By addressing the cause factors first, the company can achieve a 40% reduction in cybersecurity-related incidents within the first year, while ensuring compliance with the EU AI Act's risk-adjusted requirements.

Three main challenges exist: First, the scarcity of cross-functional experts in Taiwan's automotive sector, which can be mitigated by forming multidisciplinary task forces. Second, the subjectivity of expert ratings, solvable by using fuzzy-logic-based-DEMATEL to-quantify linguistic assessments. Third, organizational resistance to change, which requires strong leadership buy-in and a clear ROI-based value proposition. A typical implementation roadmap includes a 90-day cycle: Month 1 for factor identification, Month 2 for expert evaluation, and Month 3 for action-plan integration. This structured approach allows enterprises to be ready for TISAX certification or ISO/SAE 21434 compliance within a single fiscal year.

Winners Consulting Services Co., Ltd. specializes in DEMATEL for Taiwan enterprises, delivering compliant management systems within 90 days. Free consultation: https://winners.com.tw/contact