In this multi-part thread, I will explain the why and how of Supply Tracking in SEOW v3.1.0. Of course, like most SEOW features, it is optional so you don't have to use it if you don't want. Those players who do use it are in for an absolute revolution in the way they think about campaigning. All of a sudden you will really feel the heat if your defensive strategies fail. Failed commanders will have the horror of watching their forces literally melt away as supply shortages bite. Welcome to SEOW!
What is supply?
In SEOW, we use the word "supply" to represent all materials, services and logistics required by any unit to maintain a state of mobile combat readiness. Thus "supply" represents an amalgam of fuel, ammunition, medicine, food, radio support, maps, clothing etc. Units "in supply" are able to manoeuvre and fight; units "out of supply" become immobile and passive. If a unit stays out of supply long enough, it will eventually either "desert" (i.e. destroy its weapons and vanish into the landscape) or "surrender" (destroy its weapons and march into captivity forever).
Simply for convenience, supply is measured in litres and is often referred to as "fuel". We deem that any object's maximum supply capacity is equal to its fuel tank capacity in litres. For example, a Ba-10 armoured car has a fuel tank capacity of 60 litres so its maximum supply requirement is 60 litres, while a bicycle has a supply capacity of 12 litres. You will find a complete list of fuel capacities inside the Object_Specifications table of SEDB31. The terms "supply" and "fuel" are interchangeable in SEOW. Running out of fuel is identical to running out of supply; being refueled is identical to being resupplied.
What units use supply?
All units in SEOW use supply at all times, no matter whether they are immobile, mobile or in combat. Of course, the rate of supply usage is different according to the unit status. Immobile units have a low rate of supply usage, while mobile units have a higher rate. Even units being freighted still use supply! The good news is that the supply loads carried by all units, all industrial facilities and all airbases are tracked automatically by SEOW down to the last litre - all commanders are responsible for is making sure that supplies reach the units that need them in good time. Sounds easy, eh?

But the devil is in the detail. Commanders must schedule explicit movements of freighters/transports to load, ferry and drop off supplies. Of course, not all units can carry freight, so suddenly we see that transport ships, vehicles and aircraft become very high-value targets. In this sense, a P.11C can be as effective at tank-killing as an IL-10. All the P.11C has to do is strafe the fuel trucks that are resupplying the enemy tanks. Without supplies the enemy tanks will soon grind to a halt, stop shooting and then desert or surrender.
OK, enough generalities, let's see how all this works in SEOW v3.1.0.

DCSv3.1.0 Supply Tracking Support
Fuel/Supply tacking is turned on using the DCS tool; the option is under the Supply tab:

Clicking the topmost checkbox "Enable Fuel Supply Tracking" makes all the settings below visible. First there a two global settings. The "Global fuel consumption rate" is a number that multiplies all calculations of fuel consumption for all units on the map. Values greater than 1.0 mean that supply is used more rapidly than normal, while values less than 1.0 means that supply is used less rapidly. In the image above, the value is set to 1.6.
The "Supply Conversion Factor" is a number that expresses a single freight weight point as the equivalent number of litres of supply; set to 10000 litres in the image above. For example, a tramp steamer which has a default freight carrying capacity of 32 freight weight points could be used to carry 32x10000 = 320000 litres of supply with this setting.
Then follow two Morale settings that are used at the initialization stage. Morale is entwined in the supply model. Unit morale states are Excellent, Good, Average, Poor, Desperate. If a unit runs out of supply, its morale will drop down a level per mission. If a unit is resupplied it morale will climb one level each time it is resupplied. The presence of morale-influencing units (medium and heavy flak, command cars, civilians) can also assist or hinder morale state. Any unit that drops to Desperate morale state is in danger of desertion or surrender, depending on proximity of enemy units.
Underneath that is the "Fuel Supply Initials" panel. This panel contains settings that are used to specify the initial supply holdings in all units and facilities on the map, for each side. For each side there is a "Fuel Reserves" slider which determines the initial volume of supply held offmap for each side. These reserves can be transported onto the map using freight transportation units (ships, vehicles, aircraft) according to their individual freight capacities. Players cannot "buy" more fuel reserves!
Then there is a slider for Initial Unit Fuel Load, a percentage value which is applied to each unit's maximum fuel capacity to determine the initial fuel holding in litres for each unit. Template initialization can lead to industrial installations being controlled by either side, or left as neutral. Sliders are provided for determining the initial Infrastructure Fuel Load of fuel installations, based on the maximum capacity multiplied by the slider percentages. The same sliders are used to determine initial airbase fuel holdings according to initial national control.
OK, that is how you set up your campaign to use supply tracking. All these sliders and settings need to be configured BEFORE loading your campaign template.
For advanced campaign designers, there is a new table in the database called Sector_Movement_Cost. This table specifies individual movement costs for each sector and season (summer/winter) for sea and ground movement types. For example, winter sea movement in Murmansk is, by default, 2.5 times more demanding on fuel than summer sea movement. Campaign designers can edit the values in this table according to their scenarios, but there is no interface for adjusting these parameters inside the DCS - a database edit is required.
In the next part of this thread, I will show how the supply settings translate to MP unit display and planning functions...
Cheers,
4Shades