Modulation assistance is widely employed to improve chip management in turning. This process is also known as modulated turning. Modulated turning transforms continuous cutting into intermittent cutting by periodically disengaging the tool tip from the workpiece, resulting in the generation of short, easily managed chips. This novel method improves the machining efficiency such as final product surface texture, machining stability, and tool life. However, these benefits rely are contingent upon the fundamental principles of machining. A thorough analysis becomes necessary to evaluate the process outputs of modulated turning. This thesis presents the mechanical and thermal modelling of the modulated turning. The analysis begins with kinematics of the modulated turning. A generalized chip formulation is presented to predict uncut chip thickness, cutting forces and tool engagement/disengagement periods. Then, heat generation in modulated turning is modelled to predict tool temperatures. The time dependent heat transfer problem in cutting tool is solved both analytically and numerically. A comparative study is conducted to assess the accuracy of both developed methods, and they are validated against experiments available in literature. The effect of modulation parameters on the tool temperature is also investigated. The results show that modulated turning plays a key role in controlling maximum temperature on the rake face of the tool.