CASE STUDY CONCEPT: Military Logistics 101 — Napoleon said, “An army marches on its stomach.” In the spirit of that saying, lets look at the campaigns of Alexander the Great.
For those who think Alexander’s greatness was due only to his ability to dream up bold moves and cut a dashing figure in the saddle, think again. Alexander was a master of logistics and supply chain management. He could not have succeeded otherwise. Authors from Greek and Roman times who recorded his deeds had little to say about something so apparently unglamorous as how he secured supplies for his army. Yet, from these same sources, many little details can be pieced together that show the overall supply chain picture and how Alexander managed it.
Modeling Alexander the Great’s Supply Chain
A modern historian, Professor Donald Engels, investigated this topic in his book Alexander the Great and the Logistics of the Macedonian Army (1980, Los Angeles, CA: University of California Press). Using information from Professor Engel’s book, we created a model of the supply chain that supported Alexander’s campaign into Afghanistan and Central Asia.
As this case begins, it is the year 329 BC. In the previous year Alexander defeated the Persian King Darius, and now he’s organizing a supply chain that draws on the farms and workshops of Persia to support his advance into Afghanistan and beyond. The screenshot below shows the supply chain he has created so far. This case study will give you insight into what Napoleon meant when he said, “An army marches on its stomach.” An army can only go where there are supplies to feed it (or it will starve).
NOTE: This is an advanced case. Work through the three challenges of the beginning case, “Cincinnati Seasonings” before taking on the challenges in this case.
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The orange arrows on the screenshot above show Alexander’s planned route of march. His first objective, Kabul, is circled in yellow. Opposite Kabul on the other side of the screen, notice the blue routes lines that all converge on what is now the Afghan city of Herat. This is where Alexander established his logistics base from which he supported his campaign into Afghanistan and Central Asia.
Alexander Used Logistics as a Competitive Advantage
Alexander’s army had a logistics structure that was fundamentally different from other armies of the time. In other armies the number of wagon drivers, tradesmen and camp followers was often as large as the number of actual fighting soldiers. This was because armies traveled with huge numbers of carts and pack animals to carry their equipment and provisions. And those carts and pack animals needed lots of people to tend them. In the Macedonian army the use of carts was severely restricted. Soldiers were trained to carry their own equipment and provisions. Other contemporary armies did not require their soldiers to carry such heavy burdens, but they paid a price for this because the resulting baggage trains reduced their speed and mobility.
The result of the Macedonian army’s logistics structure was that it became the fastest, lightest, and most mobile army of its time. It was capable of making lightning strikes against an opponent often before they were even aware of what was happening. Because the army was able to move quickly and suddenly, Alexander could use this capability to devise strategies and employ tactics that allowed him to surprise and overwhelm enemies that were numerically much larger.
The picture that emerges of how Alexander managed his supply chain is an interesting one. For instance, time and again the historical sources mention that before he entered a new territory, he would receive the surrender of its ruler and arrange in advance with local officials for the supplies his army would need. The city of Herat in Afghanistan was founded by Alexander at the start of this campaign to be the main supply depot for his army of some 64,000 troops and about 10,000 cavalry horses. Added to this were wagon drivers, warehouse workers and other camp followers equaling perhaps another 35,000 people plus pack animals such as camels, horses and mules for pulling wagons and carts. This number of people and animals requires hundreds of tons of food and water every day.
Herat was a logical place to locate Alexander’s main supply depot as shown in the screenshot below. It was a central place to collect supplies from the surrounding regions, and was itself a large food producing area. Supplies coming from Persia in the west followed roads going east along the river. Supplies were also delivered by roads coming from agricultural areas to the north and east. The flat plain at the foot of the mountains where these roads came together was also next to a river crossing. So all these factors made Herat a good place to build the warehouses needed to store the supplies brought in to feed and equip the army.
Next to these warehouses there were buildings to house the people who worked there, and shops and taverns to serve them. On a rocky ridge overlooking the city, Alexander built an impressive citadel to guard the city and house the troops who defended it (shown below). He named this new city Alexandria Ariana. From here supplies were loaded onto wagons and pack animals and sent south on the route through the desert toward Kabul that was used by Alexander’s soldiers.
If a region did not surrender to him in advance, Alexander would not commit his entire army to a campaign in that land. He would not risk putting his army in a situation where it could be crippled or destroyed by a lack of provisions. Instead, he would gather intelligence about the routes, the resources, and the climate of the region and then set off with a small, light force to surprise his opponent. The main army would remain behind at a well-stocked base such as his supply depot at Herat until Alexander secured adequate supplies for it to follow.
Supply Chain Estimates and Assumptions
We will make some simplifying assumptions about Alexander’s supply chain in the initial model we build here. You can change any of these numbers in the model to use other assumptions, and you can also break the generic unit of inventory into different product categories such as rations, equipment, clothing, ammunition, etc. We’ll use the following estimates to define the operating parameters for the model:
- Products will be represented by a generic unit of inventory which is a mix of required products in a 1 cubic meter package. We’ll call this inventory “All Purpose Materiel” (APM)
- 1 unit of APM has a cube volume of 1 cubic meter and cube weight of 40 kilograms
- 1 unit of APM can sustain 5 people for a day; each person requires 0.2 units of APM per day; that’s 8 kilos of supplies per person per day
- 500 units of APM will support 2,500 people per day, and it takes 2,000 units of APM per day to support 10,000 people per day, etc.
- Alexander wants to take 20,000 soldiers on this campaign; some of these soldiers will be at the head of the advance to do the fighting and some will be spread out along the length of the advance to protect the supply line
- 44,000 soldiers and approximately 30,000 drivers, workers and camp followers will remain in Herat and continue to consume APM every day
- Supply chain vehicles are wagons drawn by horses or mules; a wagon has a carry volume of 5 cubic meters and a carry weight of 200 kilograms
- An average of three people (drivers and workers) is needed to operate and maintain each wagon, so assign APM demand for those numbers of people to facilities where wagons are based
- A wagon has a speed of 3 kilometers per hour, and vehicles can be defined as units of 25, 50, 100, 200 wagons or combinations of such units
- Assume the pack animals will eat and drink from forage and water they find in Herat and along the supply chain routes
- This means supply chain routes should follow rivers as much as possible, and appropriate forage and water must be available at facilities where large numbers of wagons are based
- The route shown for Alexander’s march on Kabul is the only practical route to move and supply 20,000 troops using the technology available to Alexander
Operating costs in the model are estimates made for the purpose of providing some idea of the money required to run this supply chain and pay the soldiers it supported. Alexander’s campaign in Afghanistan and Central Asia was funded by the gold, silver, grain and tax revenues he acquired when he defeated King Darius. Costs in this supply chain are denominated in the ancient Greek coin called the drachma, which consisted of approximately 4.3 grams of silver. You will get a sense of what it cost to pay for this campaign – war was never cheap.
Historians estimate the wage for a Greek soldier or skilled worker at this time was about one drachma per day plus room and board (in 2020 a private in the US Army earned about $55 per day plus room and board and benefits). Lower skilled workers earned one half to one quarter drachma per day. Based on these wages, plus equipment expense, and assuming a wagon could travel about 30 kilometers per day, we estimated a transportation cost of 3.5 drachmas per kilometer for 100 wagons, 7 drachmas per kilometer for 200 wagons, etc.
Rents and operating costs are assigned to facilities that are directly under Alexander’s control. There are other facilities that surrendered in advance to Alexander, but none of Alexander’s troops are stationed there and they are not directly under his control. So no rent or operating costs are assigned to those facilities because their operation is not Alexander’s responsibility. However, there is a cost assigned to the wagons from those cities as explained above. Assume this cost was the going rate charged for transportation. Alexander would have paid that cost to get suppliers to make deliveries of APM to his warehouses.
Alexander once said, “My logisticians are a humorless lot for they know if my campaign fails, they are the first ones I will slay.” Imagine you are in charge of Alexander’s supply chain… He has sketched out what he wants to do, and now he’s looking to you to create and operate the supply chain that will support his Afghan campaign. How will you deliver the supplies his troops need to succeed?
FIRST CHALLENGE:
Alexander wants to bring up troops and supplies to capture Kabul
OBJECTIVE: Design a supply chain that supports 5,000 logistics workers who operate the supply chain, 3,000 troops who defend it, and 17,000 troops concentrated at a staging area to attack the fortress at Kabul. Get the supply chain to run for 15+ days.
NOTE: There was no fortress at Kabul when Alexander passed through, but we introduce the fortress and its capture as a way to explore a (relatively) simple initial logistics problem. That problem is the support of a large body of troops concentrating in a single location before a battle. As the case progresses, we will move on to tackle more challenging logistics problems such as supporting columns of troops on the march.
As the campaign begins there are factories set up in three locations in Persia to produce food, weapons and other needed materiel. Inside Afghanistan there is the main supply depot established in Herat, and smaller depots in Shindand, Delram and Kandahar. And there are military bases at Moqor and Ghazni. For this challenge we focus on an advance force of 20,000 troops out of Alexander’s total army of about 64,000. The screenshot below shows Alexander’s supply chain as he advanced into Afghanistan toward Kabul. It shows operating results from the first run of the supply chain simulation as it is imported from the library.
We can see the depot at Kandahar runs out of APM on the ninth day (red circle over Kandahar indicates a point of failure). Supplies on hand are being consumed and shipped out faster than they are delivered to Kandahar. Yet supplies in Herat are being delivered from the surrounding territories in large quantities as shown in the on-hand inventory graph shown on the screenshot above. But supplies are not moving through the supply chain to Kandahar and Kabul in sufficient quantities to keep up with daily demand and shipping activity. More supplies need to be delivered from the main depot at Herat.
As shown in the screenshot above you set up five facilities on the route from Herat to Kabul. You picked locations where there are already supplies of food and water and other material produced by the local inhabitants. This means there will be some on-hand APM at these locations. That will help as you move supplies up to the forward base where the 17,000 troops will mass to attack the fortress at Kabul. Zoom in on the base at Ghazni and you will see two icons. One is the Ghazni supply base and the other is the Kabul Attack Force as shown in the screenshot and insert below.
Alexander (and many generals since then) called his attack force the “tip of the spear”. Click on its facility icon and drag/drop it to a forward staging area to position it for the attack on Kabul. Pick a location within the yellow circle around Kabul. This is about a day’s march outside of Kabul. The troops will move up to this point, prepare for their attack for a day or two and then launch their attack on the fortress at Kabul. The attack and capture of the fortress may take a few days. During this time, you need to deliver enough supplies to the staging location to meet the daily demand for APM to support these 17,000 soldiers. Plan to support these soldiers for 15 days.
When you look for a forward staging location for the troops zoom in and turn on the satellite view. Look for a location where there might already be some supplies available. When you position this unit of troops in your chosen location click on the icon and open the facility dialog box. Note the daily operating cost (17,000 drachmas per day), and the demand per day for APM (17,000/5 = 3,400). There is already 13,600 units of APM on-hand; this is the supplies the troops brought with them when they marched from Ghazni to the staging location. There are wagon vehicles at the Ghazni supply base to move APM up to the forward staging location and support the troops for two weeks. When you position the attack force near Kabul, the delivery route for the vehicles will follow the roads to the position you select.
As you create this supply chain and run simulations you will get a feeling for what it was like to run a supply chain under the conditions in which Alexander and his soldiers operated. In many ways things have not changed that much for modern armies (even though the wagons move faster, and some of them can fly).
Things to Think About:
- Existing facilities can be expanded by increasing their storage capacity so supplies can be stockpiled in them to support deliveries of supplies to facilities further along the supply chain.
- How much total production of APM is required to meet the total daily demands of this supply chain? How will you source APM product from the available farms and workshops to meet overall demand?
- You may need to increase APM production at facilities in Persia and in the region around Herat. If you do need to increase production, what would that increase be?
- You can change the number of wagons based at different facilities, and create new wagons at any facility in the supply chain.
- Pick a location for the forward staging base and explain why it is a good location.
- When you establish this forward base there is enough APM on-hand to support the 17,000 troops there for three days, more supplies need to reach the base before supplies run out
- Demand for APM at each facility is set based on the number of troops, wagon drivers and workers stationed at those facilities. As you change troop levels and wagons at each facility remember to adjust daily demand for APM at these facilities
- As a general rule, the closer you get to Kabul the more troops you need at a facility to protect it and escort the supply convoys
- Initially the supply chain model shows demand for APM based on these troop assignments:
- 250 troops at Shindand
- 250 at Delram
- 1000 at Kandahar
- 500 at Moqor
- 1000 at Ghazni
- There is also demand generated by 3 people for each wagon assigned to each facility
- Change demand at these facilities if you change the number of troops and wagons assigned to each facility
- How many wagons do you need and where will you base these wagons? How many people do you need to operate and maintain those wagons?
- What will Alexander say when you tell him how many wagons you need?
Download your simulation data to create mission reports showing supply chain costs and performance levels. Your main objective is to make sure there are always enough supplies everyday at every facility. But Alexander also wants you to run an efficient operation. If you can save a few drachmas here and there, Alexander will hear about it and reward you. The mission reporting template for this campaign is shown below. Costs are shown in GREEK DRACHMAS – GRD.
Download a copy from Google Docs here – https://docs.google.com/spreadsheets/d/1rYTPAl-kX6N1MQnYwhXzN6w6045kqnPzm3DrEPHmuQ8/edit?usp=sharing
As you add new vehicles and delivery routes you will need to expand the spreadsheet template to accommodate these additions. This mission reporting template will be helpful for analyzing simulation results from the first two challenges. Look at how the reports read the simulation data – you will see how to change the spreadsheet as needed.
[If you are using SCM Globe Professional version, mission reports can be generated automatically by clicking on the “Generate P&L Report” button on the Simulate Screen]
(click on screenshot to see larger image)
NOTES FOR USING THE MISSION REPORTING TEMPLATE — In addition to the original P&L report and KPIs, there are new features in the Mission Reporting template as described below:
- Ordering cost – an estimate of how much it costs an organization to place an order, receive the order, issue payment and put away the inventory delivered. Different companies have different ordering costs; estimates can range from $15 to $150 or more. Industry trade associations can provide data on average ordering costs for companies in their industries, or your company may already have an ordering cost it uses for EOQ calculations. The template uses a default cost of $35.00.
- Annual holding costs – often estimated at 20% of product price. Industry trade associations can provide data on average annual holding costs for companies in their industries.
- EOQ Delivery Amount and Frequency — these features use data from the supply chain model plus the ordering cost and holding costs to apply the Economic Order Quantity (EOQ) equation to suggest an amount and frequency for product deliveries to different facilities. The numbers are only suggestions and often need to be adjusted, but they provide a starting point. See more about this in the online guide section “Cutting Inventory and Operating Costs“, scroll down to the heading “Use Economic Order Quantity to Calculate Delivery Amounts and Frequencies”
SAVE BACKUP COPIES of your supply chain model from time to time as you make changes. Click “Save” button next to your model in Account Management screen. There is no “undo”, but if a change doesn’t work out, you can restore from a saved copy. And sometimes supply chain model files (json files) become damaged and they no longer work, so you want backup copies of your supply chain to restore from when that happens.
SECOND CHALLENGE:
Alexander says you are asking for too many wagons – do more with less!
OBJECTIVE: Reduce use of wagons as much as possible while still delivering supplies needed to support 17,000 troops at the staging area outside Kabul for 15 days.
HINT: Alexander and other armies of that time lived off the land. They requisitioned local supplies from the towns and cities they passed through. From your work on the first challenge you can see why. It takes a huge number of wagons to transport all the supplies needed by an army. So it is best to requisition supplies of food, wood, cloth, leather and other commodities from local sources. Use wagons only to carry the hard to find or make items such as heavy weapons, armor, tents and cooking utensils.
It would also be helpful to find new sources of supply closer to Alexander’s area of operations. Notice there are two facilities just to the south of the supply chain delivery route. Both of these facilities are located in or near fertile desert farming areas made possible by irrigation works built by the local inhabitants. One is called Zarangea (modern day Zaranji) and the other is Gamsir
Switch to the satellite view (button in upper left corner of screen) and zoom in on these facilities. See the green, agricultural land following along the course of the rivers as they flow through the desert landscape. These two facilities are large producers of APM and they can deliver supplies to the army. The screenshot below shows a satellite view of the agricultural land around Gamsir and a route for delivering supplies from Gamsir to Kandahar.
Alexander timed his campaign to begin early in the spring as the first harvests of winter wheat were made and the grain became available at storehouses in the cities he passed through. Assume most of the APM needed by the army (about 80 percent) is food, water and other material (cloth, leather, wood, metal) that could be acquired locally. Alexander’s army carried some of their supplies, such as armor, weapons and tents, and they requisitioned or purchased the rest of what they needed from villages and cities along the way. The screenshot below shows a satellite view of Gamsir and the productive farming made possible by irrigation works that diverted water from the river to the grow grain and vegetables in the fields along the river valley. Click on Gamsir in the Edit screen to see how much APM it produces.
In all these screenshots notice the green strips of cultivated land that follow the rivers through this otherwise desert landscape; that is where much of the food and other supplies were (and still are) produced. Assume you can meet 80 percent of demand for APM from locally produced sources. This significantly reduces the demand for wagons to move APM over long distances. And if the soldiers carried some of the APM themselves it further reduces the demand for wagons. Assume each soldier can carry weight up to 30 kg and volume up to 0.2 cubic meters.
Acquiring Supplies Locally Reduces Need for Wagons
In the supply chain model the facilities each have daily production rates for APM to represent the amount of food and raw materials they produce. Assume the Zarangea facility has 200 wagons available for delivering APM to another facility such as Delram. Assume there are 150 wagons available at Garmsir and they can be used to supply APM to Kandahar (and because these wagons and drivers are based at facilities outside of Alexander’s direct control Alexander is not responsible for their supply needs, they get that from their own facilities). Also assume Kandahar itself produces 900 units of APM per day itself because as shown below, you can see it is situated in the middle of a green agricultural region like Garmsir. Enter that production amount for the Kandahar facility in the Edit screen.
Note that the facilities between Kandahar and Kabul are located in agricultural areas that support some production of food and raw materials. Switch to satellite view and zoom on the route the army took to advance on Kabul. Assign daily production rates for APM to each facility based on how much green land you see around it; the more green land the higher the production rate. Use Garmsir, Zarangea and Kandahar as points of reference for your estimates – see how much bigger or smaller the areas of green land around other facilities are to to those three reference facilities.
Things to think about:
- How much APM do you estimate can be produced at facilities such as Shindand, Delram, Moqor and Ghazni to support the troops? Make you best guess and explain why.
- When you create a new facility for the forward base outside Kabul look for a location with some potential for APM production.
- If 80 percent of needed APM can be acquired locally, then how many wagons and drivers are required to make this supply chain work?
- How much can you reduce APM production at farms and factories in Persia and around Herat?
- How many troops would you station at each facility to protect it and why?
- For ideas on how to expand this supply chain see “Tips for Building Supply Chain Models” for useful techniques. There are also useful ideas to be found in the section “Reducing Inventory and Operating Costs”
Download your simulation data to create mission reports showing supply chain costs and performance levels. There is a reporting template that you can download. Modify as needed if you have added or removed facilities to your supply chain model – https://docs.google.com/spreadsheets/d/1rYTPAl-kX6N1MQnYwhXzN6w6045kqnPzm3DrEPHmuQ8/edit?usp=sharing
[If you are using SCM Globe Professional version, mission reports can be generated automatically by clicking on the “Generate P&L Report” button on the Simulate Screen]
THIRD CHALLENGE:
Alexander wants to capture Bukhara and Samarkand
OBJECTIVE: Alexander will take a fast, light force of 4,000 cavalry and 7,000 infantry and move north toward the cities of Bukhara and Samarkand (circled in yellow). Troops and a minimum number of wagons will carry all the equipment they need (armor, tents, weapons, utensils) and make rapid advances to surprise and confuse their opponents. The troops will buy or requisition their supplies from the cities they pass through (80% of daily APM requirements). Define routes of advance that meet the army’s supply requirements and enable the army to advance quickly on the two cities. Create a plan that merges battle strategy and logistics to give Alexander the advantage he needs on this campaign.
Alexander’s forces will need to cross over the Hindu Kush mountains north of Kabul so find mountain passes they can use. Once over the mountains, there are many cities and agricultural areas where supplies can be acquired. Identify routes through those cities for the army as it makes its way to Bukhara and Samarkand.
Assume 6,000 troops are needed to capture Samarkand and 5,000 are needed to capture Bukhara. The mix of cavalry and infantry is open as long as at least 1,000 cavalry troops are present in the battle for each city. Find routes for 6,000 troops to reach Samarkand and 5,000 troops to reach Bukhara. Explore sending troops on multiple routes for different sized units. These routes must enable units to converge in appropriate numbers at the two cities within a day or two of each other.
You will find that a good way to live off the land is to divide your army into groups that each have smaller logistics footprints. Napoleon used this approach to feed his armies as they crisscrossed Europe to do battle with his opponents during the Napoleonic Wars (1803 – 1815 AD). Martin Van Creveld describes this in his book Supplying War: Logistics from Wallenstein to Patton, 2nd Ed, Cambridge University Press, 2004. See chapter two, “An Army Marches on Its Stomach”, pg 40.
We are modeling a special sort of supply chain here. It is composed of a series of one-time, one-way transactions that occur as Alexander’s army travels across the landscape toward its objectives. The only thing that matters is creating a plan of advance where all units are able to pick up the supplies they need as they travel, enabling them to reach their assigned cities in a timely manner.
Formulating Your Plan of Advance
The screenshot below (using the map view with the Terrain feature turned on) shows the route through the mountain passes that Alexander and his soldiers used to cross the Hindu Kush mountains. This is the route all the units will use for crossing the mountains
Their destination on the other side of the mountains is the vast plains of Central Asia, and the rich agricultural and trading cities that spread out across those plains. Alexander’s troops made their way over the mountain passes as quickly as they could, and carried the food they needed with them because there is little food to be had in the high mountains. The scenery as shown below is awe inspiring, but the nights are cold and the air is thin.
Once over the mountains, the army emerged onto the plains near the present city of Kunduz as shown in the screenshot below. The long river in front of them was known as the Oxus (now the Amu Darya). Where do you think Alexander would choose to cross the river (and also get food for his soldiers when he crossed)? He chose to cross the river at the spot where the modern city of Termez now stands. A city stood there in Alexander’s time too, and it was a rich food producing area so Alexander knew he could get food for his troops as he passed through.
QUESTIONS: If you were opposing Alexander, where would you concentrate your army and how would you deliver the supplies it needs? What route(s) do you think Alexander will take as he moves toward Bukhara and Samarkand? Would you plan to stop him as he tries to cross the river, or would you pick a different location? Do you see why answers to these questions will largely define the strategy and plan of action for someone opposing Alexander?
After crossing at Termez, Alexander could go northwest along the river as one possible route of advance to reach Bukhara. But that is the route an opponent would most likely expect him to take, so it would be more strongly defended. To enable Alexander to surprise and overwhelm his opponent, what other routes can you find to advance on Bukhara? And what route would you pick for the advance on Samarkand? Would you advance first on Bukhara and then on Samarkand, or would you split your force and have different units advance on each city simultaneously?
Modeling and Simulating Your Plan of Advance
In the screenshot below (map view with Terrain feature turned off) you can see the road network that exists today. In many cases, maybe most, the existing roads follow in the tracks of ancient roads and trails. That is because the ancient roads followed river valleys and the flattest land, and took the shortest routes between cities whenever possible. That is why modern roads also use those routes; they are still the best way to travel across this landscape. We will use the modern road network as a good estimate of the routes that were available to Alexander. You can also create new roads if you wish, but make sure they are roads Alexander’s army could handle. Long stretches of waterless desert and steep mountains are not routes that an army on foot or horseback could handle (they’re hard on modern armies too).
Because the army is living off the land and not staying in any location as it moves toward the two cities, a good way to model this supply chain is to think of different sized units in Alexander’s army (500 men, 1000 men, 2000 men etc.) as being vehicles. These vehicles can use different routes to get to their final destinations of Bukhara and Samarkand. The starting location for all vehicles is Kabul. Find routes that support different sized vehicles as they move from facility to facility on multi-stop routes that advance them toward their assigned cities.
Assume units of Alexander’s army can carry up to four days of supplies with them. We know the force of 11,000 soldiers is composed of 4,000 cavalry and 7,000 infantry. Represent units of cavalry as a medium size truck with a speed of up to 10 km/hr., and for infantry units use a large truck with a speed of up to 5 km/hr. Plot routes for these vehicles to follow. Given the speeds at which units can move and the distances involved, it will take some number of days for these units to travel from one facility to the next.
You can see travel times and distances in the Edit screen when you create a route between two cities (you will see round-trip times and distances so divide by 2). Use those travel times to calculate pick-up quantities at each stop on a unit’s route of advance. If it only takes half a day to reach a given facility, then the vehicle picks up half its daily needs. If it takes 3 days, it picks up three times its daily needs. And remember, a unit does not have to pick up supplies at every facility it passes through, but no unit can go for more than four days without resupply from a facility it does pass through. Cavalry units can travel longer routes if necessary and infantry units need somewhat shorter routes if both are to arrive at their mutual destinations within a few days of each other.
Line of March is Guided by Considerations of Supply
As a general rule, you want to pick routes that follow rivers and go from one green agricultural area to the next as units move toward their assigned cities. The facilities on the routes you choose must be productive enough to generate adequate on-hand inventory to fill the pick up amounts of the units (vehicles) that pass through. Assign each facility a daily production rate and an initial on-hand amount of APM related to the size of the farmland surrounding the facility.
Estimate initial on-hand amounts of APM based on the amount of green farmland surrounding these facilities. Make educated guesses about the size of the spring harvest for each facility and deduct some APM to account for local demand, the remainder is the initial on-hand amount. Use the facilities of Gamsir and Zarangea as the basis for your estimates. How much more or less green agricultural land do you see around other cities as compared to Gamsir and Zarangea?
You will need to zoom in and look at these cities and their surrounding agricultural areas carefully. The more surrounding farmland, the higher is the initial on-hand amount of APM, and the higher the daily production rate. Make your best estimates and be prepared to explain why you made those estimates.
Create a plan where the simulation shows all units can reach the city they are assigned to attack in a timely manner. The simulations need to show all units can make their trip while picking up the supplies they need at stops on their routes. Show the planned route of advance for each unit as a multi-stop delivery route. A vehicle representing a unit will have the city it is assigned to attack as the last stop on its multi-stop route.
Consider dividing the army into smaller groups. This way each group has a smaller logistics footprint so there are more choices in selecting possible routes of advance. This gives Alexander more options for strategy in the campaign. It plays to a major strength of his army which was the ability to surprise and overwhelm larger opponents by moving quickly over the landscape because of its lighter and more agile supply chain (fewer wagons, less equipment, soldiers trained to carry more).
Notes for Building this Model
When each unit vehicle reaches its assigned city it records its arrival by dropping off some number of APM packages. Make the drop off quantity equal the number of soldiers in the unit. Once a unit vehicle reaches its assigned city it will then return to Kabul, but those return trips can be ignored. Make the delay between departures for each unit vehicle a large number (1,000 hours). So the unit vehicles will return to Kabul where they will wait and not depart again during the period of the simulation.
By looking at the timing of on-hand amounts of APM at Samarkand and Bukhara you can see when each units arrives, and whether they arrive in enough strength within 1 or 2 days of each other as called for by Alexander’s campaign strategy. Keep modifying your vehicles and routes until you find lines of advance for the unit vehicles that enable them to arrive at each city in the required numbers within a few days of each other.
See Tips for Building Supply Chain Models and scroll down to the Routes section to see tips for creating vehicle routes between facilities if there are no existing roads on the map. But if you create a new route where no road currently exists make sure it is a route that an army on foot or on horseback could handle. Zoom in and turn on the Terrain feature and the satellite view to study the land over which your route will travel.
Set vehicle carry weights and volumes to a very large number to accommodate the amounts of APM they will pick up. In this model APM production rates at facilities and vehicle speeds and pick-up quantities are the determining factors, not vehicle carry weights and volumes (the APM picked up would be consumed day by day anyway). Also set storage capacity at Kabul to a very large number to handle the amount of APM on the returning unit vehicles.
Things to think about:
- Assuming the amount of APM on-hand at Kabul was captured intact, how long could Alexander’s troops occupy Kabul before needing to be resupplied? Given the rate of APM production by Kabul itself, how many troops can it support without additional supplies from elsewhere?
- If the whole army stayed in Kabul for two days, and then moved on leaving 4,000 troops behind to guard the fortress, how many days would the remaining supplies of APM support the troops who stayed in Kabul?
- Remember – you still need to keep the supply chain working to support the troops in Kabul and the other facilities along the supply chain stretching back to Herat
- How much of the APM supplies in Kabul could the departing troops take with them to consume on their march? How many days travel can they get with these supplies?
- What are the best places in between Kabul and Bukhara and Samarkand where troops could find food and other supplies?
- Would it be best to keep the army together in one group and advance first on one city and then the next – or is it best to divide the army into smaller groups that each advance independently on their assigned city? Why?
- If you decide to divide the army into smaller units, explain how you would reconcile that decision with the classic advice, “don’t divide your forces in the face of a superior foe.”
- What routes of advance will you recommend to Alexander? What advantages do these routes offer – logistical and strategic?
The reporting template will be less useful for analyzing simulation results from the third challenge. In the third challenge the only thing that really matters is to find routes that enable all units (vehicles) to reach the last stop on their multi-stop routes — the cities they are assigned to attack. Units need to arrive at their assigned cities within a day or two of the other units also assigned to attack those cities.
As you work with this model and identify the possible routes Alexander’s army can take you will see why battle strategy and logistics are so tightly intertwined. You will appreciate how logistics affected strategy in Alexander’s time — and how it still does today.
To share your changes and improvements to this model (json file) with other SCM Globe users see “Download and Share Supply Chain Models”
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Register on SCM Globe to gain access to this and other supply chain simulations. Click the blue “Register” button on the app login page, and buy an account with a credit card (unless you already have an account). Scan the “Getting Started” section, and you are ready to start. Go to the SCM Globe library and click the “Import” button next to this or any other supply chain model.