The military services rely on major training exercises to assess their units’ strengths and weaknesses. These exercises generally take place at combat training centers that often enable units to train in an environment that closely parallels that of actual warfare. The primary centers used for conducting major exercises include (1) the Army’s combat training centers at Fort Irwin, California; Fort Polk, Louisiana; and Hohenfels, Germany; (2) the Marine Corps’ Air Ground Combat Center at Twenty-nine Palms, California; and (3) the Air Force’s Weapons and Tactics Center at Nellis Air Force Base, Nevada. The Navy conducts major training exercises at the Naval Strike Warfare Center in Fallon, Nevada, and during worldwide fleet operations. Joint military exercises are conducted at many worldwide locations, including Germany, South Korea, Egypt, and Central America. The services use electronic instrumentation, observers, and subject matter experts to monitor and record the results of the exercises so that they can objectively document performance. Additional information on the services’ capabilities is obtained from the results of actual military operations, such as Operation Desert Storm. The services document the results of military training exercises and operations in after-action reports, which include lessons learned information. The units use such information in preparing for operations and environments associated with their assigned combat missions and in tailoring training for anticipated future missions and events. In addition, lessons learned information can help the services and the Joint Staff identify recurring weaknesses in key areas. The services and the Joint Staff can then publicize problem areas and deficiency trends, allowing others to benefit from their experiences, and institute corrective actions. According to senior military leaders, weaknesses can be addressed through changes to such areas as doctrine, training and education, tactics, leadership, and materiel. Our prior work has revealed that the Army has not effectively used lessons learned information to eliminate recurring deficiencies and change doctrine, revise tactics, or develop improved training strategies. In September 1993, we reported that, although the Army was doing a good job of identifying lessons learned, it was not achieving the maximum benefit from the lessons in terms of changed doctrine or revised training practices because it lacked procedures for prioritizing the lessons and for tracking necessary changes in training and doctrine. In July 1986, we reported that Army assessments of exercise results identified many recurring deficiencies, yet the Army had not developed a system to identify causes of and solutions to problem areas. Each service and the Joint Staff has its own program for incorporating lessons learned information into its operations. The Department of Defense (DOD) has no regulations that establish policies for or require uniformity among the services’ lessons learned programs. Since no overall guidance exists, the services have taken different approaches to developing and operating their programs. However, even though the programs differ, the services and the Joint Staff use after-action reports as the primary source of information for their programs. As an example, Army lessons learned program guidance states that lessons learned programs should (1) effectively gather, analyze, disseminate, and use lessons learned information so that actions can be taken to correct deficiencies and (2) have a means for testing or validating whether the corrective action actually resolves the deficiency. The Army’s lessons learned program started in 1986. It is run by the Center for Army Lessons Learned, which is operated by the Training and Doctrine Command. The Center has a staff of about 25 civilian and military analysts that collect observations from exercises and operations, develop trends of deficiencies, and publish the results of its analyses in bulletins and newsletters that receive widespread distribution throughout the Army. The Marine Corps’ lessons learned program started in 1989 to centralize lessons learned information and address deficiencies identified in after-action reports. The program is managed by the Marine Corps Combat Development Command and staffed with four full-time personnel. The program collects, processes, and disseminates lessons learned information throughout the Marine Corps through the use of Compact Disc—Read Only Memory (CD-ROM) technology. The Marine Corps also prepares special lessons learned reports for users on specific subjects, such as the Hurricane Andrew disaster in Florida and Operation Restore Hope in Somalia. The Navy’s lessons learned program was established in 1991 at its headquarters in Washington, D.C., and reorganized in 1993 under the direction of the newly established Naval Doctrine Command in Norfolk, Virginia. The program is run by two naval officers at the Doctrine Command and a civilian who manages the database. In addition, four of the Navy’s major commands serve as management sites for lessons learned information. These sites screen lessons learned information submitted by naval units and decide, within their respective area of authority, what information is appropriate for the Navy’s lessons learned database. The Navy’s program collects, evaluates, and disseminates lessons learned information on operational and tactical issues. Similar to the Marine Corps, the Navy distributes its lessons learned information to users through CD-ROM technology. The Air Force’s lessons learned program is the only one of the services’ programs that is decentralized. As a result, each of the Air Force’s six major operational commands is responsible for developing and managing its own lessons learned program. Air Force regulations do not require that the commands’ programs be uniform, so each command can take different approaches to operating its program. In fact, the four major commands that we visited or contacted during our review all had different lessons learned programs. The programs were designed to account for, act on, and share lessons learned information throughout the command, but not throughout the Air Force. The staffing levels for the lessons learned programs varied from one to three individuals. The Air Force also operates a limited lessons learned program at its headquarters. This program, which is staffed by two people, addresses lessons learned information that results only from the Air Force’s participation in joint exercises or operations or that affects more than one of the major commands’ missions. The Joint Staff established the Joint Center for Lessons Learned to maintain and manage a centralized database on lessons learned information from joint military operations and exercises. This information, which includes ways to improve practices or overcome problems, is disseminated periodically among the services. The Center is staffed with two military analysts and one contractor representative who are assisted, when necessary, by representatives of each military service. We reviewed the lessons learned programs in the military services and the Joint Staff to determine their effectiveness in (1) collecting all significant lessons learned information, (2) analyzing lessons to identify recurring weaknesses, (3) disseminating lessons to all potential users, and (4) implementing corrective action and validating results. To do so, we reviewed the regulations and program guidance related to the lessons learned programs within each service and the Joint Staff and the policies and systems that implement the regulations and guidance. We determined how the services and the Joint Staff obtain, document, and input lessons learned data from participants in exercises and operations into their lessons learned programs. We examined the extent to which the services and the Joint Staff analyzed lessons learned information to develop trends that could highlight recurring deficiencies. Furthermore, we examined the methods and mediums the services and the Joint Staff used to provide lessons learned information to their units and analyze outputs provided from the systems. We reviewed individual lessons learned reports contained in service and Joint Staff databases that showed the results of exercises and operations. We used this information to identify recurring deficiencies, including those that could affect the success or outcome of an exercise or operation. We also examined whether the services and the Joint Staff had remedial action systems to address deficiencies. We determined whether remedial action systems had procedures for measuring the effectiveness of solutions that were developed for deficiencies. We interviewed service officials who managed the lessons learned programs to obtain their views on the programs. We also obtained the views of Army, Air Force, and Marine Corps officials at combat training centers as they repeatedly observed the performance of large numbers of units. In addition, we interviewed the leadership of selected units that participated in large-scale training exercises to determine how they used lessons learned information to improve their performance and how they generated lessons learned from their training or operational experiences. (See app. II for a list of the military organizations we visited or contacted during our work.) Information about the Army’s lessons learned program, however, is based primarily on issues developed in our September 1993 report and limited follow-up discussions with officials at the Center for Army Lessons Learned. We performed our review from December 1993 to December 1994 in accordance with generally accepted government auditing standards. The effectiveness of the services’ lessons learned programs varies considerably. The Marine Corps, Air Force, and Navy programs provide only limited assurance that significant lessons documented in combat training center analyses, fleet exercises, and after-action reports are included in their databases. This information is extremely important since, in several instances, it discloses weaknesses displayed by many units during their most important training exercises—those conducted at the services’ combat training centers. Some of the weaknesses, if not corrected, could have serious consequences on a real battlefield. Until the services take steps to ensure that all lessons learned information is collected in their databases, units will continue to miss a significant opportunity to avoid repeating past mistakes. The cornerstone of Marine Corps’ ground unit training is the combined arms exercise conducted at the Air Ground Combat Center, which provides extensive ground training to units about once every 2 years. From this training, Marine Corps evaluators and senior leaders assigned to the Center prepare several reports, which include lessons learned information, that are not included in the Marine Corps lessons learned database. This information could be extremely valuable to commanders preparing for a future combat training center rotation, since it documents tasks that commanders did not perform well and provides examples of successful practices used by others to avoid similar problems. Moreover, the reports summarize performance trends over time and include independent observers’ assessments of the performance of weapon systems and the effectiveness of doctrine. However, these reports are not routinely included in the Marine Corps’ lessons learned database. Some of the weaknesses discussed in these reports, if not corrected, could have serious consequences on a real battlefield.