Ingalls' Production Planning and Control System assists in planning, scheduling, budgeting and tracking each work authorization developed to support the construction of each ship. The system is comprised of modules that have specific functions within the System and some of the modules interface with other modules. At the nucleus of Ingalls Production Planning and Control System is the Consolidated Data Base which provides all data that is required for the other modules.

This paper addresses the key functions of a closed-loop production and inventory, and planning control system generally applicable to the shipbuilding industry. A key feature of the shipbuilding closed-loop system is the application of made-to-order concepts not generally used in production and inventory planning, and control systems for other industries. The use of modular packaged software to make the system operational on a timely step-by-step basis are explored. Special considerations for tailoring the software to satisfy general shipbuilding requirements are reviewed. A summary of the potential benefits of a closed-loop system (i.e., "what if" planning) is also included.

Private shipyards are under heavy pressure to improve productivity. So are the naval shipyards. Like the private shipyards, naval shipyards are focusing on improved production planning, scheduling, labor/progress data collection, and industrial engineering as the main thrust of their productivity improvement programs. Unlike the private shipyards, however, the naval shipyards are drawing heavily on the use of computers to support these functions. One project, the subject of this paper, is of particular interest since a computer is used to integrate planning, scheduling, work-in-process tracking and labor collection functions with engineered labor standards to provide a closed-loop production control system for a key production shop at the Portsmouth Naval Shipyard. This system achieved operational status during the spring of 1980. A complete economic history of its initial economic justification, development and operating costs and preliminary indications of payback are now available. Since the design of this system makes it quite appropriate for private shipyard use, the data included within this paper should be of interest to those concerned with the economics of computers in private shipyard production control functions. Results of this project are correlated with the objectives and results of the National Shipbuilding Research Program.

Small and medium sized shipyards (200 to 1000 employees), particularly those growing rapidly from hands-on control by a few managers to a size requiring delegation of authority to superintendents and foremen, find that they have all the management control problems of the major shipbuilders but without the staff and administrative resources to easily cope with them. Typically we find the small shipyard operating at best with a schedule covering a few key events, no integration of engineering output with production needs, an accounting system which accepts cost charging to few accounts but without budgets or work packages to control scope, schedule and manning, drawings without bills of material and every supervisor in the company participating as a material expeditor. Although the depth of detail required in a small shipyard planning and production control system will vary with product complexity, personnel strengths, and contract construction period, the basic elements of a sound system are markedly similar and cannot be ignored without incurring loss of performance.

In March of 1976, the decision was made at Port Weller Dry Docks to purchase an in-house computer system to expand our use of computer programs and to update our present systems. At that time two systems were in operation at Port Weller. The accounting and labor distribution programs were executed on a Litton-McBee paper tape oriented computer system, and the production planning and control, numerical control, and design programs were executed on a UNIVAC 1108 time sharing system using a remote batch terminal for data transmission.

WORK-PAC, Work Planning and Control System, is a complete computer software package designed to improve shipyard labor planning and to monitor labor charges against planned estimates, measure job progress and give notice to both real and potential labor over-runs and schedule slippages. WORK-PAC permits a ship repair/conversion or new construction project to be broken down into discrete work orders, which can be classified under any given set of work cost account categories: steel work; piping, electrical and machinery systems; outfit; design/drawing; and yard support services. To further facilitate labor scheduling and control, WORK-PAC allows these work orders to be assignable to specific ship zones and shop work centers. The input of planned manhours (with or without trade estimate detail) and scheduled start and finish dates and the actual manhours from timecards as applied to these work orders completes the planning feedback cycle that is tailored to shipyard operations. WORK-PAC accumulates labor charges by individual trade, differentiating between regular and premium manhours. In addition, a special WORK-PAC feature provides for separate accounting of job repair end re-work efforts as required. WORK-PAC generates numerous reports and analyses for various. levels of the shipyard organization and at various levels of detail. WORK-PAC issues automatic warnings of data errors and signals areas of budget over-runs and/or schedule slippages early in the production cycle before they become critical and while they are still resolvable.