Joint Conflict & Tactical Simulation (JCATS)

During the mid-1970s, Lawrence Livermore Laboratories’ computer scientists, were working at the Conflict Simulation Laboratory, developing a realistic software for the Department of Defense. The Laboratory’s landmark Janus program, developed in the late 1970s, was the first conflict and tactical constructive simulation to use a graphical user interface. Since then, Livermore experts have remained at the forefront of combat simulation development by taking advantage of steady advances in hardware and software and by working closely with military officers to understand their needs.


The Livermore simulations have proved highly valuable to US military as they have been employed in Operation Just Cause in Panama and Operation Desert Storm in the Middle East – Iraq, as well as for operational planning evaluation in Somalia, Bosnia, and other military operations throughout the world.

In 1997, a team of computer scientists from the Laboratory’s Nonproliferation, Arms Control, and International Security (NAI) Directorate unveiled Livermore’s most known constrictive simulation combat program. JCATS (Joint Conflict and Tactical Simulation) merged and upgraded the capabilities of two earlier programs, the Joint Conflict Model, an advanced version of Janus, and the Joint Tactical Simulation, an urban conflict model. The outcome was a model that incorporated important new features requested by its DoD sponsor, the Joint War fighting Center (JWC) in Fort Monroe, Virginia, that conferred greater fidelity to the simulations.

JCATS was mainly used to rehearse possible military operations in support of the 1999 Kosovo conflict. It was also used by the Marine Corps and the Navy to plan for and participate in an exercise in the San Francisco Bay Area. During the exercise, JCATS tracked the live participants and tested in real time the effects of virtual air and artillery attacks on the participants. JCATS takes physics into account for computing and presenting the battle outcomes in addition to stochastic models. Typical computer games may look impressive with flashy three-dimensional effects, but they don’t always observe the laws of physics. A typical PC game soldier can jump off a 15-meter cliff without a scratch, but a soldier in JCATS doing the same thing will be badly injured. Neither do commercial games take into account such seemingly mundane but crucial factors as fatigue, inclement weather, low food supplies, or poor visibility.


JCATS realistically simulates the capabilities and limitations of armaments, people, and the environment, but there are several fields that its capability to represent tactics and doctrines is obvious. This is the reason why a significant programming effort is required for supporting exercises scenarios or advanced training activities. The effectiveness of every weapon, from a laser-guided missile to a single bullet, is determined by probability-of-hit and probability-of-kill statistics compiled by DoD. Using these data, JCATS calculates, for example, the blast area and resulting casualties from tripping a land mine. Just as easily, the program calculates if a launched antitank weapon misses the tank, destroys it, incapacitates the tank’s movement but leaves its gun free to fire, or destroys the gun but leaves the tank’s mobility intact. Virtual soldiers face hazards from fatigue, enemy and friendly fire, poor health, and inadequate training. Every soldier begins with a certain amount of energy, which is expended more quickly during running or walking uphill. Players can bring in medical assets to attend to the sick or wounded.
In recognition of possible modern enemy capabilities, JCATS can simulate the release of chemical or biological warfare agents as well as other substances that might by employed as poisons during acts of terrorism or warfare. For example, the program can display how exposure to an atmospheric release of a nerve agent can affect personnel. Such capabilities make it useful for developing both military and civilian preparedness and responses.
An important disadvantage  of JCATS is that comes as a direct descendant of Janus, a model with lots of issues regarding its structure, modeling process and functionality as well as its incapability to be used from operational military personnel than computer experts. On the other hand JCATS is a software that gives commanders a realistic training tool, but is not cost-effective and operator-friendly.

JCATS is currently used for training both individuals and command staffs in tactics and deployment of resources, analyzing the effectiveness of weapons and different force structures, and planning and rehearsing missions. Besides military scenarios, JCATS can also simulate non military operations such as, drug interdiction, disaster relief, peacekeeping, counter terrorism, hostage rescue, and site security. Current users include the Army, Air Force Security Forces, Special Operations Command, Marine Corps, Naval Post Graduate School, U.S. Southern Command, U.S. Army Europe, Department of Energy, and Secret Service, NATO and a set of countries that the model either was offered as a US – nation military cooperation assistance or as an ally contribution to the nation’s Armed Forces.