Manufacturing Execution System (MES) is the major tool used to increase the effectiveness and efficiency of the operation management for the Steel Industry. Prior to implementing the MES, correctly estimating the MES Software Project Size is an important first stage and is a complex exercise. Several methods have been proposed to help in evaluating MES Software Project Size before implementation, such as function point analysis and fast function point analysis approaches. Among them, the fast function point analysis is a prominent approach. However, the detailed guideline for the use of it is lacking. Therefore, this study presents a methodology which provides these guidelines and uses it to estimate the MES Software Project Size in the Steel Industry. The research methodology is articulated using the design science research methodology. A usability evaluation is performed using three steel industry cases to demonstrate its applicability. With this enhanced approach, IT professionals or adopting organizations can more easily and systematically estimate the MES software project size.