In the production chains, a Standard Recipe (SR) defines one unit of a process. It sets the ratios of all the input and output products.
Every process has one or more input products, given in units of each input required per Standard Recipe.
For example, the Water Electrolysis process has 9kg per SR of Water as an input.
Every process has one or more output products, given in units of each output nominally produced per Standard Recipe.
For example, the Water Electrolysis process gives 8kg per SR of Oxygen and 1kg per SR of Hydrogen.
If a process has multiple outputs (as only Refinery processes do), a primary output must be selected, leaving all the other outputs as secondary outputs. The amount actually obtained of the primary output will be exactly what the process Standard Recipe specifies, but the amount of secondary outputs obtained will be diminished compared to the nominal amount specified.
When setting up a process to run, a number of Standard Recipes of the process is selected, setting “how much” of the process will be run.
For example, if 1 SR of the Water Electrolysis process is run, 9kg of Water will be required, and a nominal 8kg of Oxygen and 1kg of Hydrogen would be produced (in reality less for the selected secondary). If 1000 SRs of Water Electrolysis are run, 9000kg or 9t of Water will be required, and a nominal 8000kg or 8t of Oxygen and 1000kg or 1t of Hydrogen produced.
In general, if you know the Standard Recipe for a process, and how many SRs of the process are being run, it is easy to calculate how much of each input is required and how much of each output is nominally produced, by simply multiplying the two.
The number of Standard Recipies selected to run a process does not need to be an integer. In case a non-integer number of SRs is chosen, the input quantities will be rounded up and the outputs rounded down.
For example, if 0.5 Standard Recipes of Water Electrolysis are run, you might expect it to require 4.5kg of Water and to nominally produce 4kg of Oxygen and 0.5kg of Hydrogen. However, due to rounding, it will require 5kg of Water (inputs are rounded up), and nominally produce 4kg of Oxygen and 0kg of Hydrogen (outputs are rounded down, even if they would produce 0!)
Process nominal runtimes follow a linear equation, y = Mx + B.
The constant-time portion B is the same no matter how many SRs of a process are being run. The linear-time portion Mx increases with the number x of SRs of that process being run.
Every process has its own M and B values.
For example, Water Electrolysis has an M value of 0.0156 ingame hours per SR, and a B value of 2 ingame hours per SR. If 1000 SRs of Water Electrolysis are run, the nominal process runtime will be y = Mx + B = 0.0156 h/SR * 1000 SRs + 2h = 17.6 ingame hours, or 44 real-life minutes.
Keep in mind that bonuses and penalties will increase or decrease the runtime, and that it does not include transport times for the Crew or materials.