The technological advancements in Industry 4.0, specifically in the areas of Industrial Internet of Things (IIoT) and Artificial Intelligence (AI) enables a series of enhancements in production management. The development of Big Data, Fog & Cloud Computing and Neural Networks have made Predictive Maintenance (PdM) an area of interest as it has been able to effectively transform and adapt to machine conditions. This paper presents a systemic literature review of the state of the art in AI and IIoT regarding PdM to serve as a basis for future work in the area. The relevance of this subject is still high, as seen by the number of publications in the last two years, however there are still several relevant research challenges to be addressed, in particular to achieve an adaptable and homogeneous PdM model.