 The article proposes a new model for evaluating hole cleaning efficiency during vertical and directional drilling operations. This model, called cutting transport ratio, CTR, is based on the concept of fluid flow and can be used to identify potential problems with hole cleaning before they become serious. The model has been successfully tested and validated in the field for four different wells, demonstrating its effectiveness in identifying potential issues with hole cleaning and improving drilling efficiency. This article was authored by Muhammad Al-Rabai'i, Muhammad Al-Shargabi, and Deyfer Al-Sharri.