LEARNING CURVE MANAGEMENT ON CONSTRUCTION COST REDUCTION IN LNG STORAGE TANKS GESTION DE LA COURBE D'APPRENTISSAGE POUR L'EXECUTION DE LA CONSTRUCTION DE RESERVOIRS DE STOCKAGE DE GNL

摘要

Unlike in other areas, construction performance and learning factor analysis in LNG tank construction have been limited, compared to their important roles in LNG facilities. The LNG tank construction cost is the largest single cost in a receiving terminal. The specific construction cost of LNG storage tanks have decreased with an increase in storage capacity. However, quantitatively utilizing the past experiences in cost estimation and profitability analysis was a long term unsettled task in LNG projects. Learning curve resources were accumulated by Kogas and KBR from three different types of storage tanks: membrane type aboveground tanks, 9% Nickel full containment storage tanks, and membrane type in-ground tanks (total 28 tanks, each type built at the same site). Case based construction analysis was performed in view of tank type, construction method, construction duration, accumulated experience, storage capacity, and other parameters that affect construction performance. This paper presents the effects of the Learning Curve Management (LCM) on construction performance and cost reduction based on past experiences. A re-learning factor is incorporated in the learning function and the ultimate level of performance has been implanted in the new model of the learning curve. This paper demonstrates that the LCM, derived from the case based construction analysis, provides a reasonable basis of cost analysis, cost estimation, and profitability studies, all of which are related to the evaluation of future costs and confidence level in an analysis.