Assessing the sustainability level is now an essential procedure for improving sustainability practices in a certain industry. The stone and marble industry is one of the most important industries in Palestine, its contribution to the overall industrial revenue is 25%, and it employs directly about 25,000 workers. This paper presents a customized model to assess and improve sustainability level in stone and marble facilities. It uses an assessment tool (performance criteria) in the form of a checklist with impeded weighted scoring scale. The tool covers six main themes: energy, water, waste, transportation, site management and landscape, and human health and safety. Based on the assessment level, the model suggests a specific "To-do list" targeting the areas of improvement with the greatest potential to help the facility to improve to the next better level.