The path taken by the German Army in its advance on Moscow in the opening phase of World War II was largely dictated by logistics. The regional transportation network of railroads and paved highways existing at that time had three major hubs that controlled the movement of supplies: Minsk; Smolensk; and Moscow (circled in red in the screenshot below). So German strategy called for the capture of Minsk and Smolensk as necessary stepping stones to support the advance on Moscow.
Minsk was captured as planned in the first two weeks of the invasion, and at the end of the third week the German Army was poised to take Smolensk, its next objective. Army Group Center was responsible for this drive on Moscow. It was following a tight timeline in order to advance quickly and be in Moscow before the severe Russian winter set in. In the screenshots above and below the German and Russian units are shown in their starting positions at the beginning of the battle.
The battle occurred in the region around the city of Smolensk over a period of two months. The German Army had already advanced 500 km (300 mi) into the USSR in the previous three weeks. It was using blitzkrieg tactics that called for fast and continuous movements of armored columns and motorized infantry units to keep the enemy confused, disorganized and retreating. Blitzkrieg tactics depend on continuous deliveries of supplies to support the continuous movement of troops and vehicles.
Case Study Introduction — Structure of the German Army Supply Chain
This case study focuses on the structure and functioning of the German Army supply chain. The supply chain to support Army Group Center’s attack on Smolensk (5) is shown on the screenshot below. It began with supply depots in Prussia (1) and Poland (2). Minsk at the center of the road and rail networks (3) was a forward depot. There was also a captured Russian refinery and fuel depot (4) that provided much needed gasoline, although the gasoline had to be further processed to meet German requirements. German units participating in the battle are labeled on the map in the screenshot below.
German and Russian units are displayed at the corps level in this case study. Each corps is composed of two or more divisions, and a division has 15,000 to 18,000 men (gray warehouse icons represent German corps units and gold store icons represent Soviet armies that were the equivalent of corps units).
From the screenshot above and the map below you can see the positions of the German units at the start of the battle, and the movements of those units during the battle. The arrows show where each of the German units went.
(click map for larger image) Courtesy of Livedawg, Wikimedia Commons, 6 Dec 2013, https://commons.wikimedia.org/wiki/File:Smolensk_1941_Diagram.jpg
Battle maps such as this make a dramatic impression with their sweeping arrows showing dashing movements of men and machines surging across the landscape. Yet it is important to remember that behind those arrows there are supply chains that make those dashing movements possible. Without supply chains, the combat units in those arrows would run out of food, fuel and ammunition in two or three days. Then all the dashing around would come to an abrupt halt.
Estimates of Supply and Demand
This case study is based on information presented in the book Supplying War by Martin Van Creveld, (http://www.amazon.com/Supplying-War-Logistics-Wallenstein-Patton/dp/0521546575/). In Chapter 5 “Russian Roulette”, Van Creveldt describes the logistics operation that supported Army Group Center in the battle of Smolensk. Van Creveld states that logistics support for the German units in the battle was provided by captured Russian railroads and by three German truck transport regiments. He presented the data below which is used to model these entities in this case study:
- Freight rail cars reflect the weight restrictions of Russian railways which used a smaller gauge and freight car size than what was used by the German railways. Russian freight cars carry 450,000 kg and have a volume of 1,100 m3. Average speed including loading and unloading is 35 km/hr
- A transport regiment consists of: 3,000 men; 2,200 trucks with cargo capacity of 4.5 tons and 40 m3 each; average truck speed including loading and unloading is 320 km/day or about 27 km/hr.
- Daily fuel needs for a transport regiment are estimated at 50 tons, and 25% of a regiment’s trucks are assumed to be out of service because of breakdowns or enemy action during the battle
German combat units involved in this battle consisted of six German Army corps that made up Army Group Center. Each corps consisted of two or more divisions. (https://en.wikipedia.org/wiki/2nd_Panzer_Army#2nd_Panzer_Group). These units and their estimated daily needs for supplies are shown below :
- 39th Corps – 3 motorized divisions
- 5th Corps – 3 non-motorized divisions
- 9th Corps – 3 non-motorized divisions
- 47th Corps – 3 motorized divisions, 1 non-motorized regiment
- 46th Corps – 3 motorized divisions
- 24th Corps – 2 motorized divisions, 2 non-motorized divisions
- Each corps has its own vehicles to move supplies from its main supply dump to its divisions and regiments
- Motorized armored or infantry division daily needs: food – 75 tons; fuel – 150 tons; ammunition – 75 tons
- Non-motorized infantry division daily needs: food – 75 tons; fuel – 50 tons; ammunition – 75 tons
Modeling and Simulating the German Supply Chain
In this case study we explore a supply chain modeled at the army group and corps level in order to study the overall logistics that supported the battle. This supply chain model shows the movement of supplies from army group supply depots well behind the front lines to army corps units engaged in combat. We focus first on finding ways to deliver adequate supplies to each corps before considering how those supplies would then be further distributed to lower level units within a corps.
The German supply chain is modeled by combinations of four types of entities placed on the map: (1) Products; (2) Facilities; (3) Vehicles; and (4) Routes. Examples of these entities from the model are shown below. Data for these entities is gotten from Van Creveld’s book, and data for any of the entities can be changed as needed if better information is available.
The screenshot above shows data for a group of the four entities: (1) Products – size and weight of a shipping container of ammunition; (2) Facilities – storage capacity, internal product demand, and amounts on-hand at a facility such as the Minsk Supply Depot (production of food at the depot represents food acquired locally); (3) Vehicles – cargo volume and weight, and speed of a vehicle representing 500 medium trucks; and (4) Routes – round trip time and distance on the route taken by those 500 trucks between Minsk and 5th Corps and the amounts of different products they drop off at 5th Corps.
Army group supply depots are shown with the depot icon, and army corps units are shown as warehouses placed where those units locate their main supply dumps. This model assumes each army corps has its own internal vehicles to move supplies from its supply dump to lower level units (divisions, regiments, etc). The daily product demand numbers shown for a corps represent the combined demand from all the divisions and regiments in that corps.
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- To further explore supply chain operations within a single corps, a lower level model can be built that begins with the main supply dump for a corps and shows the vehicles and routes that move those supplies to the divisions and regiments within that corps.
- That model would start with the facility that is the main supply dump for the corps, and that facility would produce amounts of products equal to the products delivered to it as shown in this higher level model.
- One must first create a successful high level (corps level) supply chain model before one can address lower level (division, regiment etc) supply chain models because if the supply chain doesn’t work at the high level, it certainly will not work at the lower level.
- Since this case focuses on the German supply chain, the logistics of the Russian army units are not considered. Russian army units are positioned in their starting positions but no numbers are entered regarding their daily demands for products nor is the supply chain shown that supported those Russian units.
- When you click on those units you see they have been set up with a nominal on-hand amount of products, but since there is no demand defined for the products and no supply chain to deliver more products, the units show no change in their product inventory levels during the simulation. However, Russian product demands and supply chain operations can readily be added to this model, see section at bottom of this case study titled “Wargaming Option“.
FIRST CHALLENGE: Get supply chain to run for 15 – 30 days
Imagine you are in charge of logistics for Army Group Center in the battle for Smolensk. Import the “Battle of Smolensk – 1941” supply chain model from the online library and open it up in your edit screen to inspect the model. Click on the menu tabs for Products, Facilities, Vehicles, and Routes. Select entities in those menus and look at their data. Zoom in on some of the facilities and switch to the map view to study their location and the surrounding area.
Then click on the “Simulation” button and run a simulation to see how well this supply chain works. You see trucks and trains running on their routes, and real time displays on the right side of the screen showing day to day inventory levels for different supplies. As the simulation is running click on some of those data displays for German supply depots and combat units to see the trends in the on-hand amounts of different supplies. You see various product inventories are trending up and others are trending down at different facilities representing army depots and combat units. Then on the sixth day (as shown below) the German 39th Corps and the 47th Corps both run out of fuel.
The first thing you need to do is get this simulation to run for at least 15 days, but not more than 30 days (because nobody knows what the situation will be beyond 30 days anyway). You need to reassign trucks to different routes to support product delivery requirements, and you’ll need to make changes to vehicle delivery schedules (change the “Delay Between Departures” number for different vehicle entities).
Keep trying things to see what works. Flip back and forth between the edit screen and the simulation screen. Make changes to the supply chain model in the edit screen, then switch to the simulation screen and run a simulation to see how it performs.
Think about using both trucks and trains to transport supplies. Do you have enough trucks to transport needed supplies? Are the current railroad freight cars being used effectively? How would you rearrange trains and their delivery schedules to move more products? Where would trains be the best mode of transport and where would trucks be better? Why?
When you get a simulation that runs for 15 – 30 days it means you have successfully created a logistics plan that will support Army Group Center in this battle for a couple of weeks or a month if everything goes according to plan. But as they say, “No plan ever survives contact with the enemy.” So you will need to continuously update your logistics plan as events unfold.
TIP: Save backup copies of your supply chain model from time to time as you make changes. Then if a change doesn’t work out, you can restore from a saved copy.
For ideas on how to expand this supply chain see “Tips for Building Supply Chain Models” for useful techniques.
SECOND CHALLENGE: Modify supply chain as events unfold
If you refer back to the battle map above you can see the movements made by each of the combat units. On that map you can see where each unit ended up at the end of the battle 60 days after the battle began. Imagine that after the first two to four weeks, some of the combat units need to establish new supply dumps to support their advancing troops.
Different corps will have different needs. Some corps traveled long distances (like the 39th Corps and the 47th Corps), and other corps (like the non-motorized 5th Corps and 9th Corps) did not travel so far. For corps that did not travel far, it may not be worth setting up new supply dumps. But for those motorized corps that did travel long distances, it is necessary to establish new supply dumps that are located half or even two thirds of the total distance those corps advanced over the course of the battle.
This means you need to find good locations for these new supply dumps – places well served by road and rail lines. Look for good locations on the map and zoom in and switch to satellite view to see more detail on specific locations. Select locations for the new supply dumps and create new facilities at those locations. Then re-route some portion of the vehicles delivering products to the old supply dumps to deliver products to the new supply dumps.
And while all this setting up of new supply dumps is going on, each corps still needs to deliver supplies to its divisions and regiments engaged in the battle. So for a period of time supplies from both the old and the new supply dumps will be supporting combat units. Divide the total product demand that existed at the original supply dump between the new dump and the original dump. Assign half of the product demand to the new dump and half to the original dump. When new supply dumps open you can assume they already are stocked with products to cover 2 days of demand.
Then run simulations to see how well the new supply chain works. Get the new supply chain to run again for 15 — 30 days. It will take some tinkering and adjusting to get the new supply chain to work. As you figure these things out you will get an understanding of what is involved in supporting an army in the field. It’s a lot harder than it might have seemed at first.
The German Army did win this battle, but it encountered unexpected resistance from the Russian Army. The battle was originally planned to take a couple of weeks during which time the Russian Army would be encircled and destroyed. But instead it became a battle that took a couple of months, leading to a serious delay in the German advance on Moscow. And a significant number of Russian troops escaped from the German encirclement of Smolensk and continued their fight to defend Moscow. As the German Army advanced further and further into Russia, its supply chains were stretched and stretched again; they struggled to keep up with the demands of their combat units.
PRESENTATION OF FINDINGS
Van Creveld states in his book (pg 152) that the German high command generally recognized “the Russians would have to be defeated within the first 500 km (300 miles) if they were to be defeated at all…” German commanders believed that after pushing 500 km into Russia they would need to pause the offensive for a few months to allow time for buildup of large new supply depots inside Russia to support their continued advance. From what you learned in this case study can you explain why they might have felt this way?
Prepare a short presentation outlining the challenges you encountered and the actions you took to respond to those challenges. Explain why you did what you did, and use screenshots and data from your simulations to illustrate what you did and your reasons for doing so. Use examples from this case study to illustrate how strategy and logistics must work together to deliver success.
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WARGAMING OPTION: Combine Supply Chain Simulations with Wargames to Enhance Understanding of both Logistics and Strategy
Wargames are usually map-based because battles and maneuvers happen on landscapes best represented as maps. And supply chains move products across landscapes that are also best represented as maps. So map-based wargames and map-based supply chain simulations provide an opportunity to combine our thinking about strategies and logistics (see more about this in a blog article titled “Lessons Learned from Wargaming” – http://blog.scmglobe.com/?p=2169).
Every strategy (or concept of operations – CONOPS) needs a supply chain to support it, and every military supply chain is built to support some strategy. Strategies define the military units involved and where they will be located and what their product demands will be. Then supply chain simulations quickly show if a particular strategy is viable given the supply chain capabilities available to support that strategy. Simulations show if enough supplies can be delivered to all units during the time period a strategy (CONOPS) is employed.
There are commercial and instructor-developed wargames that teachers of history and military strategy use to reenact and simulate various campaigns and battles. Philip Sabin in his book Simulating War (https://www.amazon.com/Simulating-War-Studying-Conflict-Simulation/dp/1472533917) makes a powerful case for using map-based wargames to study conflicts and strategies. But these wargames focus primarily on strategy and conflict tactics leaving the handling of logistics to abstract rules that only hint at the real logistics challenges.
There are several commercially available wargames that model the German invasion of Russia and major battles in that invasion such as the battle for Smolensk. Shown below is one such wargame, “Panzergruppe Guderian: The Battle for Smolensk, July 1941″ — https://australianwargamer.wordpress.com/2011/08/27/panzergruppe-guderian-battle-for-smolensk/
Student teams compete by playing the opposing sides in a wargame such as this. One team plays the German side and the other team plays the Russian side. Each team has both a battle group and a logistics group that have to work together to support overall strategy. Each team has to coordinate their battle strategy and their supply chain operations in order to win.
This means teams can only make moves in the wargame that simulations show can be supported by their respective supply chains. Teams have to tailor their strategies to meet their logistics capabilities, and figure out how to make best use of their logistics capabilities in order to create supply chains that can support desired strategies.
In this gaming and simulation exercise, teams learn to adjust their battle strategies and their supply chain operations so that both work together. People come to see that strategies and supply chains are two sides of the same coin — just as it is in the real world.
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