Enterprise level value stream mapping and analysis for aircraft carrier components

Abstract

Northrop Grumman Newport News is committed to implementing lean on the enterprise level. This thesis is focused around work toward creating a global, high-level information and material value stream map for a specified pipe assembly. It identifies the largest areas of waste in the value stream and their root causes. The recommendations assist with the reduction and elimination of the major time delays, inventory buildups, re-work, excessive processes and other waste in the system. The pipe assembly chosen as the basis for the enterprise value stream map is part of a system, newly developed for the current aircraft carrier. The pipe assembly is representative of other pipe assemblies fabricated in the shipyard, so challenges experienced with the manufacturing and flow of the selected assembly are likely to be seen in many other pipe assemblies in the facility. A large number of assemblies was examined to determine the root causes of delivery problems. The analysis was based on the criticality of the ship need date. The root causes for the late assembly delivery were found to be inadequate material inventory levels in the warehouses, lack of fabrication timeline coordination between fabrication shops, late engineering drawing revisions, underestimated fabrication durations, late supplier delivery, late material purchase order placement, and lost material. Suggestions are provided to improve operational efficiencies by targeting the elimination of these root causes that result in the delay of assembly fabrication. Some include material ordering process reorganization, shop loading variability elimination, fabrication timeline alignment, metric realignment, and rework system prioritization. Recommendations for future work focus are

(cont.) concentrated on the control of the stock material inventory levels, alignment of the incentives across the enterprise, and reorganization of the planning processes.