This study aim to apply Time-Driven Activity-Based Costing (TDABC) in Syrian industrial environment to define the ability of (TDABC) in recognition ofidle resources and calculating the cost of it, because of the critical role of this recognition in reducing production cost and inducing entity’s competitive force. (TDABC) has been applied in one of the industrial entities in Damascus Rural. Applying (TDABC) in this entity led to the presence of unused production capacity in one of the entity's sections which representing 27% of the total costs of the resources division, in addition to determine the cost of this unused production capacity, while the adopted accounting cost system in the entity couldn't discover unused production capacity in any section of entity. This study revealed that (TDABC) succeeded in defining idle resources in the chosen entity, and showed the simplicity of applying this method.