Industry 4.0 (I4.0) ideas are incorporated into the latest developments in sustainable supply chain management. In order to improve the supplier selection process, this Thesis creates an integrated model that takes into account both sustainability and Industry 4.0 characteristics. The suggested technique utilizes a combination of the neutrosophic entropy method, Evaluation Based on Distance from Average Solution (EDAS), and VIseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) methods, PROMETHEE II to evaluate criteria and suppliers. The first step of this research is to identify and define all of the factors associated with Industry 4.0 and sustainability (criteria). The neutrosophic entropy determines the weights of criteria. After that, EDAS and VIKOR, PROMETHEE II methods are used to rank suppliers based on their performance in accordance with sustainability and Industry 4.0 requirements. New and effective, the EDAS is a technique for MCDM. In this approach, the attractiveness of options is calculated by measuring their separation from a mean solution. When it comes to optimizing complex systems across several criteria, the VIKOR approach was created. With the original (provided) weights, it calculates the compromise ordering list and the compromise outcome. PROMETHEE II is an outranking method that builds a preference relation by a consecutive alternative pairwise comparison. We give an empirical analysis to illustrate the usefulness of our integrated approach. Lastly, comparative study is performed to show the effectiveness of the proposed methodology. This study helps the decision makers in the fields of I4.0 and sustainability. Also, the influence of COVID-19 has been felt in many facets of personal and professional life. As a result of the international economic crisis and the pandemic's consequences, major supply chains (SCs) have been disrupted. Our study intends to examine the effect of COVID-19 on SCs and help organizations choose options depending on their relative relevance. Phase one and phase two of the investigation are the most important. As a first step in strengthening SCs' ability to withstand the pandemic, Phase 2 examines the difficulties, concerns, actions, and solutions that have been encountered so far. As part of this phase, a MARCOS method is proposed to select solutions that address the complex interrelationships that are involved in decision-making. Positive and negative solutions are considered, and it is at the start of the creation of a preliminary matrix, utility degree is determined closer to both solutions, a new method of determining utility functions and their aggregates is proposed, and the method is stable enough to take into account a huge list of conditions and alternatives. Using this approach, decision-makers will be able to weigh the relevance and influence of many options more properly before making a final choice. The findings suggest that SCs should continue to rely on innovation to endure potential competition and disasters.