The VLS Tech-Assist Expert System

The vertical launch system (VLS) is the U.S. Navy’s premier missile launch system for surface ships. The VLS is modular, and its configuration is tailored to the individual ship. Depending on ship type or class, ship configurations have one or two launching systems. A ship can carry between 61 and 121 missiles. At the end of fiscal year 1993, about 73 systems were deployed on 46 ships; these numbers will almost double in the next 5 years. The VLS Department of the Naval Surface Warfare Center–Port Hueneme Division is the in-service engineering agent (ISEA) for the VLS. Among its life-cycle support activities, the ISEA provides technical assistance to the fleet in resolving VLS problems through diagnosis and repair. The VLS maintenance philosophy is built on general navy safety rules and the four VLS cardinal rules of safety, all intended to ensure the safety of personnel and ordnance and prevent the possibility of an inadvertent launch. Only certified naval personnel are allowed to troubleshoot the system using ISEA-approved procedures documented in on-board manuals. When the on-board procedures are not sufficient to resolve the problem, a tech-assist message is sent to the ISEA. ISEA engineers are assigned to the case to develop additional fault isolation or repair procedures, which are then communicated to the ship to resolve or repair the ship’s problem. In the current defense budget environment, the staff level at the ISEA will not be allowed to grow and keep pace with the doubling of the VLS population in the fleet and the increased work load. In fact, for fiscal year 1994, the funding to support the VLS fleet is half of the projected amount. Coupled with the natural attrition of VLS experts, these factors place severe pressure on the ISEA to help maintain readiness in the VLS fleet. The ISEA has considered knowledge-based–system technology as a force multiplier to maintain VLS readiness in the fleet with proportionally less resources.