Different methods are used to address Quay Crane Assignment and Scheduling Problems (QCASP). In current literature often the unloading time is used to optimize QCASPs. However, this approach neglects the value of the vessel's freight. This paper therefore uses a cost based approach to optimize container terminal operations, which allows the model to focus on two objectives. The first objective is to show the impact of varying freight lead time costs on the priority of vessels and consequently the Quay Crane (QC) assignment and scheduling. The second objective is to implement adjustable QC operation costs and working rate and show the impact of particular adjustments. The model results show vessel prioritization based on the value of the vessel's freight. The variation in crane operation cost only impacts the assignment and scheduling in the occurrence of high crane operating costs relative to the value of the vessel's freight.