Lean IHOP Transformation of Shipyard Erection Block Construction

Abstract

The modern system of shipbuilding includes applying integrated hull construction, outfitting, and painting (IHOP) of ship interim products, as opposed to the traditional manner of first constructing the hull blocks, then performing basic outfitting and finally painting, all separate of each other. Even though most shipyards apply some degree of integration of all trades during vessel construction, much work could still be better integrated. This article analyzes and maps the present IHOP construction of a typical shipbuilding erection block in a real shipyard. Through the application of a product work breakdown structure and group technology, the degree of IHOP integration could be increased. This is demonstrated to be in compliance with the lean principles of improving flow and kaizen. The article will suggest how the vessel construction could be become leaner through a value stream map, thereby decreasing both duration time and man-hours, thus securing significant savings for the shipyard. 1. Introduction The concept of integrated hull construction, outfitting, and painting (IHOP) of ship blocks has existed for the past 40 years. However, the level of IHOP application differs among shipyards. There is still much rework and outfitting that is performed on the slipway or in the dry-dock as opposed to during the assembly or preerection construction phase. The main aim of IHOP is to construct and outfit and paint ship blocks to a high degree while minimizing the outfitting tasks for later construction stages. This method greatly reduces shipbuilding production man-hours which yields major savings for shipyards. The idea of IHOP derives from group technology. In the distant past, ships were built in the classic method with keel laying on the slipway followed by piecemeal steel construction with outfitting of ship equipment afterward. Outfitting includes all equipment that is not an integral part of the hull structure such as equipment foundations, pipes, cables, hangars, ladders, pumps, valves, boilers, purifiers, evaporators, bus and switchboards, diesel generator sets, the main engine, and all of the ship systems including the wheelhouse electronics and navigation equipment.