One of the most important aspects of mould design in injection moulding is the provision of suitable and adequate cooling arrangements. Proper cooling channel design in the mould is an important aspect as it affects cycle time and quality of the injection moulded plastic part. A new cooling channel design with copper tube insert can reduce cycle time by optimal and uniform heat transfer in the mould. In this research work a comprehensive FEA transient thermal-structural analysis has been performed with ANSYS simulation software to understand robustness and longevity of an industrial plastic part mould with these cooling channels and compared with conventional straight cooling channels. Autodesk Moldflow Insight (AMI) also has been used to get essential process parameter values for analysis. Result shows that by inserting copper tube in the cooling channels, a mould can increase cooling efficiency and can last for higher number of cycles before fatigue failure, thus increasing production rate.