This study aims to identify and analyse the critical success factors (CSFs) in robust service systems using the fuzzy cognitive mapping (FCM) approach. First, the factors or criteria affecting the robust service systems were identified through the literature review. Then, the cause-and-effect relationships of the factors and the effect of each factor in the robust design of the service systems were determined using the opinions of the panel of experts using the FCM approach. Findings show that 39 factors affect making a robust service system which can be classified into five categories based on the balanced scorecard (BSC) approach: social responsibility and stakeholder satisfaction, learning and growth of individuals, internal processes, finances, and suppliers. The three criteria of strengthening the process design, the competence of individuals and education and learning of individuals have the most significant impact on the robust design of the service system, respectively.