Construction of a modern warship can occupy a period of more than three years, during which time more than three million manhours may be expended, and it is necessary to control the acquisition, production and installation of some 250,000 items of material and equipment. To execute the process effectively requires an efficient means of planning and control, and this paper describes the approach to that task adopted by a United Kingdom shipyard. The concepts of Build Strategy, Work Packaging, Materials Definition, Process Engineering and Labour Cost Control, as related to the shipyard's organisation structure are explored. The paper describes the establishment and operation of a system of planning and control based on task definition.
In any job, project, program, or complex undertaking there exists a need to understand all aspects of the work. This understanding is necessary to satisfy all requirements in the most effective and efficient way. The methods available to plan and accomplish these tasks are as vary as much as the tasks themselves. They range from job shop techniques to Material Requirements Planning (MRP) to Project-Based Management Information System (PBMS) to continuous manufacturing. This paper is a critical analysis aimed at classifying two of these system approaches as they relate to the ship repair equation. Material Requirements Planning (MRP I) tracks a need for material through a project. The production process on the material determines how labor is applied to transform raw materials into finished products. MRP material needs are determined by sales forecasting; while requirements are determined algorithmically from material take-offs. Another form is Manufacturing Resource Planning (MRP II). This form of MRP is a management process, supported by computers, which results in monthly production plans based outlooks, etc., and is far sales more comprehensive in scope and integration than MRP I.
Computer Aided Design and Computer Aided Manufacturing (CAD/CAM) technologies offer significant benefits in the design, construction, and life cycle support of today's complex Navy ships. CAD provides the capability to create three dimensional (3D) product models which can realistically represent geometry and associated design data of the ship prior to construction. Building of a computer model of the ship prior to construction reduces interferences and improves design accuracy and completeness. The 3D computer models consist of geometry and associated design data for components and systems, and provide a tool to design and evaluate form, fit, and function. Efforts such as interference detection and resolution, simulated walk-throughs, change-impact analysis, and improved production sequence planning can be conducted concurrently with design development. Detail design drawings, manufacturing sketches and Numerical Control (NC) instructions can be developed and extracted directly from the design database. This reduces duplication of data, saves time, and lowers costs - for both the construction of the ship and the life cycle maintenance functions that follow. The most significant benefits of 3D CAD/CAM functions that follow. The most significant benefits of 3D CAD/CAM methodologies as applied to complex Navy surface combatants are improved design and manufacturing accuracy and consistency, which in turn result in savings in production time and cost. On the U.S. Navy's ARLEIGH BURKE (DDG 51) Class AEGIS Destroyer program, CAD/CAM technology is being implemented to take full advantage of these savings.
After years of studies, reports, formal and informal discussions, Naval ship producibility is becoming accepted as a necessary ingredient in any recipe for affordable, effective warships. However, within both the Navy ship design and private ship construction communities, the word producibility has come to evoke a wide variety of reactions. While there is general agreement that producibility has to do with lowering ship costs, there is not yet a consensus on how those costs are to be attacked, what factors are the most important, and what the roles of the various participants should be. In order to answer these and other questions, and to form a consensus within the Navy design community that will be compatible with external as well as internal relationships, the Naval Sea Systems Command (NAVSEA) has sponsored a series of steering committee meetings and a workshop on producibility as part of its ongoing research. The purpose of these meetings and workshop is to clarify the meaning of producibility, the needs of the design and construction communities, and to determine critical actions which will enable NAVSEA to integrate producibility more thoroughly into the Naval ship design process.
In quest of increased efficiency to make better use of financial resources, industry, both public and private sector, have often been turning to the industrial engineering community for help. And while there has been progress in measuring the efficiency of human resources and establishing work standards, similar efforts in the use of equipment have, in recent years, become of greater interest and will continue to do so in the coming years.
This symposium, held in Milwaukee, Wisconsin on 21-24 August 1990, was comprised of technical presentations on a variety of topics including, ship design, planning and acqusition of naval ships, environmental health and safety issues at naval shipyards, cost effectiveness, hazardous materials handling, fabrication, maintenance, life cycle maintenance, machinery for fabrication, shipbuilding materials and other topics of interest.
The cyople%%ity of shipyard operanrons, in cornhination vith the diverse and nurnerous harardous materials used in manufacturing and repair, present unique environmental, health and safety challenges. One shipyard has taken a proactive approach to harard identification, assessment and control in order to effectively manage these risks. This included a major risk screening, consequence modeling of the scenario developed and the generation of practical risk control options. Such action facilitated the development 0 a conprenensive, multi-disciplinary emergency response plan as %ll as compliance vith regulations promulgated as the result of the Super fund Amendments and Reauthorization Act of lD0SS.
American shipbuilding management and planning has become a topic of increasing discussion in recent years and various proposals for change have been advanced. Many of these propose adoption-of certain techniques and approaches successfully used --in other major shipbuilding countries such as Japan and Korea, where shipbuilding management is based on organizational, decision making, and operating structures and procedures founded on quite different cultural backgrounds, human relations, and traditions than those found in the U.S. While some of the techniques and approaches found successful in those countries may be transferrable, it must be recognized that the environment in the U.S. cannot be changed in the short run. This makes successful application of some of these methods difficult. Factors which make Japanese and Korean shipbuilding competitive include value engineering, quality circles, labor incentives, high productivity manufacturing processes; rationalized ship design and production, effective organization, labor relations and flexibility, good supplier and customer relations, and effective production planning management and control. There are some factors which are distinctly different, such as the lack of adversity between shipbuilder and client on one hand and management and labor on the other hand. There is a general recognition and acceptance in these countries that adversary relations and potential litigous actions hinder achievement of ship production efficiency and on schedule low cost (and therefore price) delivery. Similarly most supplier, client, and labor issues with shipbuilding management are resolved by various informal approaches with little if any delay. This is quite different from the generally formal approach used in the U.S.A., where procedure, documentation, and even conflict resolution methods are often defined.
