Developing a new assessment tool in the area of sustainable development requires a strategic methodology for a cohesive and logical framework incorporating relevant theory and practical experience, building on a critical analysis of the state of the art. The assessment process implies the existence of tools, instruments, processes, and methodologies to measure performance in a consistent manner with respect to pre-established standards, guidelines, factors, or other criteria. Sustainability assessment practitioners have developed an increasing variety of tools. The present paper discusses a range of fundamental approaches, as well as specific and integrated strategies for sustainability assessment, as the foundation of a new rating system being developed for large industrial projects. Assessment methods identified by different schemes are also described. The focus then shifts onto environmental and sustainable rating systems, emphasizing the more popular tools. The present work is thus a review of the status of sustainability development and its different assessment tools: approaches, strategies, models, appraisals, and methodologies. This work also presents a description of the credit weighting tool used by the most popular sustainability and environmental rating systems.