CASE STUDY CONCEPT: Military Logistics 101 — “An Army Marches on Its Stomach”
In this case study we look at how Alexander supplied his campaign in Afghanistan. The case study is based on research done by professor Donald Engles and presented in his book Alexander the Great and the Logistics of the Macedonian Army (1980, University of California Press).
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. His first objective is to capture Kabul. How will you deliver the supplies his troops need to achieve that objective?
As this campaign begins, Alexander has defeated the Persian King Darius and is organizing a supply chain to draw on the farms and workshops of Persia to support his advance into Afghanistan. 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 support it (or it will perish).
Was Alexander great because he cut a bold figure in the saddle and dreamed up great strategies? Or was it because he figured out how to keep his troops from running out of food and supplies as he campaigned against his opponents in Persia, Afghanistan and India? The answer is both – he merged his strategic thinking with his supply chain thinking so that each supported the other.
This supply chain uses factories to stand for the farms and workshops Alexander has in Persia and Afghanistan because they are the sources of production. We use warehouses to stand for his army supply depots because that’s where supplies can be stockpiled, and we use stores to stand for his military bases because that’s where the troops are who create demand for the supplies.
The route taken by Alexander on his march into Afghanistan is identified in the supply chain model for this case study – the topography makes it the only practical route through which to move large numbers of troops using the means that were available to Alexander. This is illustrated in the screenshot above. We will estimate the number of troops Alexander had and the amount of daily supplies needed for each soldier. The supply chain model is based on the actual terrain and the vehicles available at that time – slow-moving ox carts and wagons. Simulations of this supply chain show how the ability to acquire, move and stockpile supplies affects the number of soldiers that can be supported at any given location. And that strongly affects the kinds of strategies and tactics Alexander could employ in this campaign.
Let’s make some estimates and assumptions to define the operating parameters of Alexander’s supply chain. The following assumptions are already built into this simulation:
- For products we’ll use 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 Material” (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 soldiers for a day; each soldier requires 0.2 units of APM per day; that’s 8 kilos of supplies per soldier per day
- So it takes 2,000 units of APM per day to support 10,000 troops; 500 units of APM will support 2,500 troops per day
- Alexander has 14,000 soldiers for this campaign. Some of these soldiers will be at the head of the advance to do the fighting and some will be stationed at facilities along the path of the advance to operate and protect the supply line.
- Assume at least 10,000 soldiers are needed (and 12,000 would be better) to capture Kabul which is Alexander’s first objective on this campaign
- Alexander’s supply chain vehicles are wagons drawn by horses, oxen or mules; a wagon has a carry volume of 5 cubic meters and a carry weight of 200 kilograms
- A wagon has a speed of 3 kilometers per hour
- A wagon can carry 5 units of APM and support 25 troops per day
- 100 wagons can support 2,500 troops per day
- Vehicles can be units of 50, 100 or 200 wagons
Alexander Used Logistics as a Competitive Advantage
It was because Alexander’s army managed its supply chain so well that it was able to achieve its brilliant successes. Alexander’s army had a logistics structure that was fundamentally different from other armies of the time. In other armies the number of support people 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 severly restricted.
Other armies did not require their soldiers to carry such heavy burdens but they paid for this because the resulting baggage trains reduced their speed and mobility. Alexander’s soldiers were trained to carry much their own equipment and provisions. And what they could not carry, they supplemented by requisitioning supplies from the cities they passed through.
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, Alexander could use this capability to devise strategies and employ tactics that allowed him to surprise and overwhelm enemies that were numerically much larger.
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YOUR CHALLENGE — Alexander’s plan is to march to and capture the Afghan fortress at Kabul, and then move on further into Afghanistan from there. Can you create a supply chain to support this campaign? That’s a pretty theoretical question until you start playing with the design of different supply chains and learning from simulations about what works and what doesn’t.
At the start of this campaign there are factories set up in three locations in Persia to produce food, weapons and other needed material. Inside Afghanistan there are supply depots established in Herat and Shindand. And there are military bases at Delram and Kandahar. The screenshot below shows operating results from one simulation.
This simulation shows operating results from the Alexander the Great supply chain model in the SCM Globe library. We can see the depot at Herat runs out of storage space for supplies (red circle indicates point of failure), and at the same time supplies on hand at Kandahar (circled in blue) are being consumed faster than they are delivered. Two upward spikes in the otherwise downward sloping blue line on the graph show arrivals of wagons carrying supplies. But arriving supplies do not keep up with daily demand. More wagons are needed to move up more supplies, and other closer sources of supply need to be found (blue arrows).
As you extend the supply chain toward Kabul, you need to set up new facilities and deliver supplies to support the troops. Each new facility requires storage space and soldiers to protect it. As you create this supply chain and run simulations you will get an intuitive feel for what it is like to run a supply chain under the conditions Alexander and his soldiers operated in (and although the wagons are faster, things are not that different even today).
Here are some things to think about as you work with this case study:
- Existing facilities can be expanded to become depots by increasing their storage capacity so supplies can be stockpiled in them to support deliveries of supplies to facilities further along the supply chain
- Establish a forward base to hold the 10,000 – 12,000 troops who will attack Kabul. This base should be a day’s march outside of Kabul (40 – 45 km); just inside of the yellow circle around Kabul shown in the screenshots above
- How will you move up enough supplies to support those troops in the forward base for 15 days? Or 30 days?
- Define the number of vehicles at each facility and their routes and product delivery quantities.
- You may want to establish new facilities for storing supplies in between Kandahar and Kabul
- Remember to adjust demand for APM at each facility to supply the troops stationed at those facilities to protect them
- Assume the closer you get to Kabul the more troops need to be stationed at a facility to protect it and to escort the supply convoys
- Experiment with the number of wagons needed to support different allocations of troops in different facilities.
- Are you starting to understand how difficult it is to supply large numbers of troops as they advance across enemy territory?
- What will Alexander say when you tell him how many wagons you need?
HINT : Alexander and all other armies of that time lived off the land
Alexander timed his campaign to begin early in the spring as the first grain harvests 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 70 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.
To the southwest of Delram in Alexander’s day (circa 330 B.C.) there was a highly productive agricultural area known as Zarangea (a smaller area is now called Zaranji). 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. Southwest of Kandahar is a facility called Garmsir and it too is a productive agricultural region because of irrigation provided by the rivers that flow into the desert.
Assume you can meet about 70 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). Notice there are two facilities situated in fertile agricultural areas to the south of the current supply chain. Both of these places are located in or near fertile desert farming areas made possible by irrigation works built by the local inhabitants. 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.
Acquiring Supplies Locally Reduces the 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 (yellow circle) and they can be used to supply APM to Kandahar (blue circle). Also assume Kandahar produces 900 units of APM per day itself because you can see it is situated in the middle of a green agricultural region like Garmsir.
If you put new facilities in locations between Kandahar and Kabul that are also located in agricultural areas that support production of food and raw materials, then you will need fewer wagons to haul the remaining supplies needed by the army. Switch to satellite view and zoom on the route the army will take to Kabul. Look for areas that show concentrations of agricultural activity. Those make good locations for new depots and forward bases needed to support Alexander’s advance on Kabul.
Assign daily production rates for APM to these facilities based on much green land you see around these facilities; the more green land the higher the production rate. Use Garmsir and Kandahar as points of reference for your estimates – how much bigger or smaller are these areas of green land compared to Garmsir or Kandahar.
If 70 percent of needed APM can be acquired locally, how many wagons are required to make this supply chain work? How much APM needs to be produced at facilities between Kandahar and Kabul and how much needs to be delivered from other facilities to support the troops? Where would you put the new facilities and why? How many troops would you station at each facility to protect it and why?
TIP: 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. 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. There are also useful ideas to be found in the section “Reducing Inventory and Operating Costs”
SECOND CHALLENGE – Moving on After Kabul
Alexander’s plans call for the army to continue its advance after taking Kabul. The army will move north toward the cities of Bukhara and Samarkand. What ideas do you have for keeping the army supplied on that march? Design a supply chain to support the army as it advances on these two cities, and get this supply chain to run for 30 days.
Some questions to think about as you work in this second challenge:
- Assuming the amount of APM on-hand at Kabul was captured intact, how long could Alexander’s troops occupy Kabul after they took it before needing to be resupplied?
- If the troops only stayed in Kabul for four days, and then moved on leaving 500 troops behind to guard the city, how many days would the remaining supplies of APM support the troops who moved on?
- What are the best places in between Kabul and those two cities where the army 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 two groups that each advance independently on their assigned city?
- What will you tell Alexander when he asks you how many troops can be supported on this march beyond Kabul, and what routes of advance will you recommend to him?
HINT : The army needs to live off the land during its march
Pick routes that follow rivers and go from one green agricultural area to the next as you move toward these two cities so the army can acquire food and water as it goes. Also assume the army divides into two groups and each group advances separately on its assigned city.
By dividing into two smaller groups, each group has a smaller logistics footprint so there are more options to choose from 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).
This is an example of how logistics affected strategy in Alexander’s time — and often still does today.
MISSION REPORTING TEMPLATE — There is reporting template with an operations report and a performance dashboard for analyzing your simulation data. The template is built for a 15-day period. You can import your simulation data after trimming it for 15 days (scroll down to bottom of Analyzing Simulation Data). The operations report shows facility and product detail, and the dashboard shows where the best opportunities are for improvement. You can download a copy of the mission reporting template here.
The reporting template is set up for the Nepal Earthquake DR supply chain, but look at how the reports read the simulation data and you will see how to change the spreadsheet as needed to accommodate this case study.
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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