Belief rule-base expert system with multilayer tree structure for complex problems modeling.

• Propose a new representation scheme of hierarchical BRB using MTS. • Propose a MTS-BRB modeling procedure for a new BRB expert system. • Propose a MTS-BRB inferencing procedure for a new BRB expert system. • Propose a MTS-BRB learning procedure for a new BRB expert system. • Verify the MTS-BRB expert system using four benchmark problems. Belief rule-base (BRB) expert system is one of recognized and fast-growing approaches in the areas of complex problems modeling. However, the conventional BRB has to suffer from the combinatorial explosion problem since the number of rules in BRB expands exponentially with the number of attributes in complex problems, although many alternative techniques have been looked at with the purpose of downsizing BRB. Motivated by this challenge, in this paper, multilayer tree structure (MTS) is introduced for the first time to define hierarchical BRB, also known as MTS-BRB. MTS-BRB is able to overcome the combinatorial explosion problem of the conventional BRB. Thereafter, the additional modeling, inferencing, and learning procedures are proposed to create a self-organized MTS-BRB expert system. To demonstrate the development process and benefits of the MTS-BRB expert system, case studies including benchmark classification datasets and research and development (R&D) project risk assessment have been done. The comparative results showed that, in terms of modelling effectiveness and/or prediction accuracy, MTS-BRB expert system surpasses various existing, as well as traditional fuzzy system-related and machine learning-related methodologies. [ABSTRACT FROM AUTHOR]