Tag Modeling and Simulation (M&S)

Abstraction and Aggregation in Wargame Modeling

[IPMS/USA Reviews]

“All models are wrong, some models are useful.” – George Box

Models, no matter what their subjects, must always be an imperfect copy of the original. The term “model” inherently has this connotation. If the subject is exact and precise, then it is a duplicate, a replica, a clone, or a copy, but not a “model.” The most common dimension to be compromised is generally size, or more literally the three spatial dimensions of length, width and height. A good example of this would be a scale model airplane, generally available in several ratios from the original, such as 1/144, 1/72 or 1/48 (which are interestingly all factors of 12 … there are also 1/100 for the more decimal-minded). These mean that the model airplane at 1/72 scale would be 72 times smaller … take the length, width and height measurements of the real item, and divide by 72 to get the model’s value.

If we take the real item’s weight and divide by 72, we would not expect our model to weight 72 times less! Not unless the same or similar materials would be used, certainly. Generally, the model has a different purpose than replicating the subject’s functionality. It is helping to model the subject’s qualities, or to mimic them in some useful way. In the case of the 1/72 plastic model airplane of the F-15J fighter, this might be replicating the sight of a real F-15J, to satisfy the desire of the youth to look at the F-15J and to imagine themselves taking flight. Or it might be for pilots at a flight school to mimic air combat with models instead of ha

The model aircraft is a simple physical object; once built, it does not change over time (unless you want to count dropping it and breaking it…). A real F-15J, however, is a dynamic physical object, which changes considerably over the course of its normal operation. It is loaded with fuel, ordnance, both of which have a huge effect on its weight, and thus its performance characteristics. Also, it may be occupied by different crew members, whose experience and skills may vary considerably. These qualities of the unit need to be taken into account, if the purpose of the model is to represent the aircraft. The classic example of this is a flight envelope model of an F-15A/C:

[Quora]

This flight envelope itself is a model, it represents the flight characteristics of the F-15 using two primary quantitative axes – altitude and speed (in numbers of mach), and also throttle setting. Perhaps the most interesting thing about this is the realization than an F-15 slows down as it descends. Are these particular qualities of an F-15 required to model air combat involving such and aircraft?

How to Apply This Modeling Process to a Wargame?

The purpose of the war game is to model or represent the possible outcome of a real combat situation, played forward in the model at whatever pace and scale the designer has intended.

As mentioned previously, my colleague and I are playing Asian Fleet, a war game that covers several types of naval combat, including those involving air units, surface units and submarine units. This was published in 2007, and updated in 2010. We’ve selected a scenario that has only air units on either side. The premise of this scenario is quite simple:

The Chinese air force, in trying to prevent the United States from intervening in a Taiwan invasion, will carry out an attack on the SDF as well as the US military base on Okinawa. Forces around Shanghai consisting of state-of-the-art fighter bombers and long-range attack aircraft have been placed for the invasion of Taiwan, and an attack on Okinawa would be carried out with a portion of these forces. [Asian Fleet Scenario Book]

Of course, this game is a model of reality. The infinite geospatial and temporal possibilities of space-time which is so familiar to us has been replaced by highly aggregated discreet buckets, such as turns that may last for a day, or eight hours. Latitude, longitude and altitude are replaced with a two-dimensional hexagonal “honey comb” surface. Hence, distance is no longer computed in miles or meters, but rather in “hexes”, each of which is about 50 nautical miles. Aircraft are effectively aloft, or on the ground, although a “high mission profile” will provide endurance benefits. Submarines are considered underwater, or may use “deep mode” attempting to hide from sonar searches.

Maneuver units are represented by “counters” or virtual chits to be moved about the map as play progresses. Their level of aggregation varies from large and powerful ships and subs represented individually, to smaller surface units and weaker subs grouped and represented by a single counter (a “flotilla”), to squadrons or regiments of aircraft represented by a single counter. Depending upon the nation and the military branch, this may be a few as 3-5 aircraft in a maritime patrol aircraft (MPA) detachment (“recon” in this game), to roughly 10-12 aircraft in a bomber unit, to 24 or even 72 aircraft in a fighter unit (“interceptor” in this game).

Enough Theory, What Happened?!

The Chinese Air Force mobilized their H6H bomber, escorted by large numbers of Flankers (J11 and Su-30MK2 fighters from the Shanghai area, and headed East towards Okinawa. The US Air Force F-15Cs supported by airborne warning and control system (AWACS) detected this inbound force and delayed engagement until their Japanese F-15J unit on combat air patrol (CAP) could support them, and then engaged the Chinese force about 50 miles from the AWACS orbits. In this game, air combat is broken down into two phases, long-range air to air (LRAA) combat (aka beyond visual range, BVR), and “regular” air combat, or within visual range (WVR) combat.

In BVR combat, only units marked as equipped with BVR capability may attack:

  • 2 x F-15C units have a factor of 32; scoring a hit in 5 out of 10 cases, or roughly 50%.
  • Su-30MK2 unit has a factor of 16; scoring a hit in 4 out of 10 cases, ~40%.

To these numbers a modifier of +2 exists when the attacker is supported by AWACS, so the odds to score a hit increase to roughly 70% for the F-15Cs … but in our example they miss, and the Chinese shot misses as well. Thus, the combat proceeds to WVR.

In WVR combat, each opposing side sums their aerial combat factors:

  • 2 x F-15C (32) + F-15J (13) = 45
  • Su-30MK2 (15) + J11 (13) + H6H (1) = 29

These two numbers are then expressed as a ratio, attacker-to-defender (45:29), and rounded down in favor of the defender (1:1), and then a ten-sided-die (d10) is rolled to consult the Air-to-Air Combat Results Table, on the “CAP/AWACS Interception” line. The die was rolled, and a result of “0/0r” was achieved, which basically says that neither side takes losses, but the defender is turned back from the mission (“r” being code for “return to base”). Given the +2 modifier for the AWACS, the worst outcome for the Allies would be a mutual return to base result (“0r/0r”). The best outcome would be inflicting two “steps” of damage, and sending the rest home (“0/2r”). A step of loss is about one half of an air unit, represented by flipping over the counter or chit, and operating with the combat factors at about half strength.

To sum this up, as the Allied commander, my conclusion was that the Americans were hung-over or asleep for this engagement.

I am encouraged by some similarities between this game and the fantastic detail that TDI has just posted about the DACM model, here and here. Thus, I plan to not only dissect this Asian Fleet game (VGAF), but also go a gap analysis between VGAF and DACM.

The Dupuy Air Campaign Model (DACM)

[The article below is reprinted from the April 1997 edition of The International TNDM Newsletter. A description of the TDI Air Model Historical Data Study can be found here.]

The Dupuy Air Campaign Model
by Col. Joseph A. Bulger, Jr., USAF, Ret.

The Dupuy Institute, as part of the DACM [Dupuy Air Campaign Model], created a draft model in a spreadsheet format to show how such a model would calculate attrition. Below are the actual printouts of the “interim methodology demonstration,” which shows the types of inputs, outputs, and equations used for the DACM. The spreadsheet was created by Col. Bulger, while many of the formulae were the work of Robert Shaw.

The Dupuy Institute Air Model Historical Data Study

British Air Ministry aerial combat diagram that sought to explain how the RAF had fought off the Luftwaffe. [World War II Today]

[The article below is reprinted from the April 1997 edition of The International TNDM Newsletter.]

Air Model Historical Data Study
by Col. Joseph A. Bulger, Jr., USAF, Ret

The Air Model Historical Study (AMHS) was designed to lead to the development of an air campaign model for use by the Air Command and Staff College (ACSC). This model, never completed, became known as the Dupuy Air Campaign Model (DACM). It was a team effort led by Trevor N. Dupuy and included the active participation of Lt. Col. Joseph Bulger, Gen. Nicholas Krawciw, Chris Lawrence, Dave Bongard, Robert Schmaltz, Robert Shaw, Dr. James Taylor, John Kettelle, Dr. George Daoust and Louis Zocchi, among others. After Dupuy’s death, I took over as the project manager.

At the first meeting of the team Dupuy assembled for the study, it became clear that this effort would be a serious challenge. In his own style, Dupuy was careful to provide essential guidance while, at the same time, cultivating a broad investigative approach to the unique demands of modeling for air combat. It would have been no surprise if the initial guidance established a focus on the analytical approach, level of aggregation, and overall philosophy of the QJM [Quantified Judgement Model] and TNDM [Tactical Numerical Deterministic Model]. It was clear that Trevor had no intention of steering the study into an air combat modeling methodology based directly on QJM/TNDM. To the contrary, he insisted on a rigorous derivation of the factors that would permit the final choice of model methodology.

At the time of Dupuy’s death in June 1995, the Air Model Historical Data Study had reached a point where a major decision was needed. The early months of the study had been devoted to developing a consensus among the TDI team members with respect to the factors that needed to be included in the model. The discussions tended to highlight three areas of particular interest—factors that had been included in models currently in use, the limitations of these models, and the need for new factors (and relationships) peculiar to the properties and dynamics of the air campaign. Team members formulated a family of relationships and factors, but the model architecture itself was not investigated beyond the surface considerations.

Despite substantial contributions from team members, including analytical demonstrations of selected factors and air combat relationships, no consensus had been achieved. On the contrary, there was a growing sense of need to abandon traditional modeling approaches in favor of a new application of the “Dupuy Method” based on a solid body of air combat data from WWII.

The Dupuy approach to modeling land combat relied heavily on the ratio of force strengths (largely determined by firepower as modified by other factors). After almost a year of investigations by the AMHDS team, it was beginning to appear that air combat differed in a fundamental way from ground combat. The essence of the difference is that in air combat, the outcome of the maneuver battle for platform position must be determined before the firepower relationships may be brought to bear on the battle outcome.

At the time of Dupuy’s death, it was apparent that if the study contract was to yield a meaningful product, an immediate choice of analysis thrust was required. Shortly prior to Dupuy’s death, I and other members of the TDI team recommended that we adopt the overall approach, level of aggregation, and analytical complexity that had characterized Dupuy’s models of land combat. We also agreed on the time-sequenced predominance of the maneuver phase of air combat. When I was asked to take the analytical lead for the contact in Dupuy’s absence, I was reasonably confident that there was overall agreement.

In view of the time available to prepare a deliverable product, it was decided to prepare a model using the air combat data we had been evaluating up to that point—June 1995. Fortunately, Robert Shaw had developed a set of preliminary analysis relationships that could be used in an initial assessment of the maneuver/firepower relationship. In view of the analytical, logistic, contractual, and time factors discussed, we decided to complete the contract effort based on the following analytical thrust:

  1. The contract deliverable would be based on the maneuver/firepower analysis approach as currently formulated in Robert Shaw’s performance equations;
  2. A spreadsheet formulation of outcomes for selected (Battle of Britain) engagements would be presented to the customer in August 1995;
  3. To the extent practical, a working model would be provided to the customer with suggestions for further development.

During the following six weeks, the demonstration model was constructed. The model (programmed for a Lotus 1-2-3 style spreadsheet formulation) was developed, mechanized, and demonstrated to ACSC in August 1995. The final report was delivered in September of 1995.

The working model demonstrated to ACSC in August 1995 suggests the following observations:

  • A substantial contribution to the understanding of air combat modeling has been achieved.
  • While relationships developed in the Dupuy Air Combat Model (DACM) are not fully mature, they are analytically significant.
  • The approach embodied in DACM derives its authenticity from the famous “Dupuy Method” thus ensuring its strong correlations with actual combat data.
  • Although demonstrated only for air combat in the Battle of Britain, the methodology is fully capable of incorporating modem technology contributions to sensor, command and control, and firepower performance.
  • The knowledge base, fundamental performance relationships, and methodology contributions embodied in DACM are worthy of further exploration. They await only the expression of interest and a relatively modest investment to extend the analysis methodology into modem air combat and the engagements anticipated for the 21st Century.

One final observation seems appropriate. The DACM demonstration provided to ACSC in August 1995 should not be dismissed as a perhaps interesting, but largely simplistic approach to air combat modeling. It is a significant contribution to the understanding of air combat relationships that will prevail in the 21st Century. The Dupuy Institute is convinced that further development of DACM makes eminent good sense. An exploitation of the maneuver and firepower relationships already demonstrated in DACM will provide a valid basis for modeling air combat with modern technology sensors, control mechanisms, and weapons. It is appropriate to include the Dupuy name in the title of this latest in a series of distinguished combat models. Trevor would be pleased.

Assessing The Assessments Of The Military Balance In The China Seas

“If we maintain our faith in God, love of freedom, and superior global airpower, the future [of the US] looks good.” — U.S. Air Force General Curtis E. LeMay (Commander, U.S. Strategic Command, 1948-1957)

Curtis LeMay was involved in the formation of RAND Corporation after World War II. RAND created several models to measure the dynamics of the US-China military balance over time. Since 1996, this has been computed for two scenarios, differing by range from mainland China: one over Taiwan and the other over the Spratly Islands. The results of the model results for selected years can be seen in the graphic below.

The capabilities listed in the RAND study are interesting, notable in that the air superiority category, rough parity exists as of 2017. Also, the ability to attack air bases has given an advantage to the Chinese forces.

Investigating the methodology used does not yield any precise quantitative modeling examples, as would be expected in a rigorous academic effort, although there is some mention of statistics, simulation and historical examples.

The analysis presented here necessarily simplifies a great number of conflict characteristics. The emphasis throughout is on developing and assessing metrics in each area that provide a sense of the level of difficulty faced by each side in achieving its objectives. Apart from practical limitations, selectivity is driven largely by the desire to make the work transparent and replicable. Moreover, given the complexities and uncertainties in modern warfare, one could make the case that it is better to capture a handful of important dynamics than to present the illusion of comprehensiveness and precision. All that said, the analysis is grounded in recognized conclusions from a variety of historical sources on modern warfare, from the air war over Korea and Vietnam to the naval conflict in the Falklands and SAM hunting in Kosovo and Iraq. [Emphasis added].

We coded most of the scorecards (nine out of ten) using a five-color stoplight scheme to denote major or minor U.S. advantage, a competitive situation, or major or minor Chinese advantage. Advantage, in this case, means that one side is able to achieve its primary objectives in an operationally relevant time frame while the other side would have trouble in doing so. [Footnote] For example, even if the U.S. military could clear the skies of Chinese escort fighters with minimal friendly losses, the air superiority scorecard could be coded as “Chinese advantage” if the United States cannot prevail while the invasion hangs in the balance. If U.S. forces cannot move on to focus on destroying attacking strike and bomber aircraft, they cannot contribute to the larger mission of protecting Taiwan.

All of the dynamic modeling methodology (which involved a mix of statistical analysis, Monte Carlo simulation, and modified Lanchester equations) is publicly available and widely used by specialists at U.S. and foreign civilian and military universities.” [Emphasis added].

As TDI has contended before, the problem with using Lanchester’s equations is that, despite numerous efforts, no one has been able to demonstrate that they accurately represent real-world combat. So, even with statistics and simulation, how good are the results if they have relied on factors or force ratios with no relation to actual combat?

What about new capabilities?

As previously posted, the Kratos Mako Unmanned Combat Aerial Vehicle (UCAV), marketed as the “unmanned wingman,” has recently been cleared for export by the U.S. State Department. This vehicle is specifically oriented towards air-to-air combat, is stated to have unparalleled maneuverability, as it need not abide by limits imposed by human physiology. The Mako “offers fighter-like performance and is designed to function as a wingman to manned aircraft, as a force multiplier in contested airspace, or to be deployed independently or in groups of UASs. It is capable of carrying both weapons and sensor systems.” In addition, the Mako has the capability to be launched independently of a runway, as illustrated below. The price for these vehicles is three million each, dropping to two million each for an order of at least 100 units. Assuming a cost of $95 million for an F-35A, we can imagine a hypothetical combat scenario pitting two F-35As up against 100 of these Mako UCAVs in a drone swarm; a great example of the famous phrase, quantity has a quality all its own.

A battery of Kratos Aerial Target drone ready for take off. One of the advantages of the low-cost Kratos drones are their ability to get into the air quickly. [Kratos Defense]

How to evaluate the effects of these possible UCAV drone swarms?

In building up towards the analysis of all of these capabilities in the full theater, campaign level conflict, some supplemental wargaming may be useful. One game that takes a good shot at modeling these dynamics is Asian Fleet.  This is a part of the venerable Fleet Series, published by Victory Games, designed by Joseph Balkoski to model modern (that is Cold War) naval combat. This game system has been extended in recent years, originally by Command Magazine Japan, and then later by Technical Term Gaming Company.

Screenshot of Asian Fleet module by Bryan Taylor [vassalengine.org]

More to follow on how this game transpires!

Perla On Dupuy

Dr. Peter Perla, noted defense researcher, wargame designer and expert, and author of the seminal The Art of Wargaming: A Guide for Professionals and Hobbyists, gave the keynote address at the 2017 Connections Wargaming Conference last August. The topic of his speech, which served as his valedictory address on the occasion of his retirement from government service, addressed the predictive power of wargaming. In it, Perla recalled a conversation he once had with Trevor Dupuy in the early 1990s:

Like most good stories, this one has a beginning, a middle, and an end. I have sort of jumped in at the middle. So let’s go back to the beginning.

As it happens, that beginning came during one of the very first Connections. It may even have been the first one. This thread is one of those vivid memories we all have of certain events in life. In my case, it is a short conversation I had with Trevor Dupuy.

I remember the setting well. We were in front of the entrance to the O Club at Maxwell. It was kind of dark, but I can’t recall if it was in the morning before the club opened for our next session, or the evening, before a dinner. Trevor and I were chatting and he said something about wargaming being predictive. I still recall what I said.

“Good grief, Trevor, we can’t even predict the outcome of a Super Bowl game much less that of a battle!” He seemed taken by surprise that I felt that way, and he replied, “Well, if that is true, what are we doing? What’s the point?”

I had my usual stock answers. We wargame to develop insights, to identify issues, and to raise questions. We certainly don’t wargame to predict what will happen in a battle or a war. I was pretty dogmatic in those days. Thank goodness I’m not that way any more!

The question of prediction did not go away, however.

For the rest of Perla’s speech, see here. For a wonderful summary of the entire 2017 Connections Wargaming conference, see here.