Divide 60 by the number of seconds in a production cycle to get cycles per minute. Multiply that result by the amount of each ingredient the machine consumes per cycle. The answer tells you how much each upstream line must supply to keep the assembler running.
Start with the machine's current recipe
Record the cycle time and the quantity of each input. Keep the units consistent. If you add a second machine running the same recipe at the same speed, multiply each per-machine rate by two.
Work through a playtest example
A player in a recorded playtest read a circuit-board recipe with two silicon wafers and one nickel plate per three-second cycle. Twenty cycles per minute would therefore need 40 wafers and 20 plates per minute for one machine running continuously.
Compare calculated demand with delivered material
Check each ingredient at the assembler. A line may support the right rate at its source while delivering less after other machines take a share. Measure the supply the assembler actually receives before increasing its count.
See Main Sequence on Steam for the official game information.
FAQ
Can I use the example rates for every version?
Use your own recipe values. The example shows the calculation with numbers from one playtest.
Why calculate each ingredient separately?
A shortage in one ingredient slows the machine even if the other ingredient arrives faster than needed.
What changes when I add a second assembler?
If the recipes and cycle times match, the total ingredient demand doubles.