The dynamic nature of production environment makes planning activities difficult. In parallel with the technological advancements, digital twin has been increasingly used in order to offer effective solutions to production processes. This study proposes a simulation-based digital twin scheduling model for production planning in mass production systems. Thus, we aim to propose an innovative and practical approach to production scheduling which is hard to implement on the shop floor. The model is the digital counterpart of the production line and is integrated with real time production data. It considers many production parameters such as raw material stocks, production cycle times, setup times, shifts and break times, maintenance and downtimes. We provide a novel approach by combining process planning and scheduling together. To elaborate how to apply the proposed approach to reality, we present detailed implementation process of the digital twin in a fabric manufacturer textile company and determine production sequences of the jobs for knitting machines. The model makes risk analysis by considering the risk of not delivering the orders on due dates. Thus, potential delays can be avoided by rescheduling high-risk tasks.