Fuzzy, Neutrosophic, and Plithogenic Approaches to Project Scheduling, Multischeduling, and Iterative Multischeduling

This paper develops a unified framework for project scheduling under uncertainty using Iterative MultiStructures. We introduce Fuzzy, Neutrosophic, and Plithogenic Project Iterative MultiScheduling, where schedules are composed across hierarchical levels as finite multisets and evaluated after canonical flattening and selection. Using componentwise extensions of sum and max, we propagate uncertain activity times and derive fuzzy expectations and credibility constraints (and their neutrosophic/plithogenic counterparts). We prove that the schedule space forms an Iterative MultiStructure and that our models strictly generalize classical fuzzy project scheduling, neutrosophic project scheduling, and plithogenic project scheduling, as well as their non-iterative multischeduling variants. The framework supports precedence networks, multi-criteria costs, and admits exact reductions under natural embeddings.