Shipyard Mathematics: A Comprehensive Mathematical Model for Estimating Manhours in Ship Repair

Abstract

The process of ship repair involves the restoration and maintenance of vessels to ensure their operational efficiency and safety. The term "man-hour" refers to the amount of labor required for a ship to undergo maintenance services in a dockyard. The process of docking ships for maintenance and repair is a complex undertaking that requires advanced planning and techniques. Additionally, it is a labor-intensive task that must be completed under strict time limitations. This study presents the development of a mathematical model utilizing multiple linear regression modeling techniques, specifically employing the least square method, to estimate the repair man-hour of cargo ships. This study aims to examine the interdependence among various characteristics related to the estimation of man-hours required for ship repair. In this model, the ship repair man-hour is determined by various factors, including structural steel works, pipework, displacement, hull cleaning and painting, general service, underwater fitting, and ship draft. The findings of this study indicate that certain independent variables, such as the number of plate works, exert a greater influence or dominance compared to other variables, such as the beam of the ship, in influencing the man-hours required for ship repairs. This model is hypothesized to potentially enhance shipyard and dockyard management by facilitating the estimation of labor man-hours required for repairs and the associated costs and time needed for initial quotations.