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CFD simulations were conducted to study the effects of a hydrofoil and its relative placement in the longitudinal direction on the total resistance of a mono-foil hysucat (hydrofoil supported catamaran). Three foil positions were considered: (i) precisely below the vessel's center of gravity, (ii) 3 chord-lengths aft from position 1 and (iii) 6 chordlengths aft from position 1. At relatively low speed (volumetric Froude number FnV < 1.8), the hydrofoil results in an increase of the total resistance of the hysucat (up to 4.43%). At relatively high speed (FnV > 1.8), the hydrofoil results in a decrease of the total resistance (up to 34.86%). The resistance coefficient first increases, takes a maximum value and then decreases with increasing Froude number. The maximum value is observed at FnV ≈ 1.4 (or Fn ≈ 0.5), consistent with previous observations. The most optimum foil placement is that precisely below the center of gravity of the vessel.

The design of lean manufacturing system to solve the problem of inefficiency or waste in the process of ship production in Madura shipyard, with consideration because in a manufacturing system can always be found things that actually do not provide added value or things that are too excessive in doing so. This is commonly called waste workshop. Lean's approach aims to eliminate waste elimination and non value added activity, facilitate the flow of material, product and information, and continuous improvement of quality. With lean approach,  it is expected that the shipyard of kapa madura will be more efficient and productive In this research, a simulation model for lean manufacturing in SME Madura shipyard was developed. Development of simulation model is done with ARENA software. To measure the lean manufacturing system performance that was designed, experiments and optimization were carried out using the Response Surface Methodology. The measurement of multi performance criteria with the Analytical Hierarchy Process (AHP) method with work in process criteria, waiting time, and flow time is carried out to determine the optimal lean manufacturing system. From the completion of the AHP method, it can be seen that the weight for the waiting time criterion is 0.7; flow time 0.2, and Work in Process 0.1. The weight of each criterion generated from the AHP method multiplied by the response of each criterion will be A weighted performance measure (WPM). Based on the optimization graph in the Response Surface Methodology method, Global Solution or the optimal solution is obtained using Minitab 16 software as follows : A (Set Up Time) = 2 (80 minutes), B (Lot Size) = -1.51515 (8 tons), C (Loading interval) = -1.23232 (208 minutes), D (Demand Stability) = -2 (90%), With the value of the goal for the minimum WPM, the lowest value is 0, the target value is 0 and the upper value is 11000

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