Productivity modules add a second purple "production bar" at item producing buildings and labs. It fills at the speed of (production - 100%). When it reaches 100%, an extra item (or items, in recipes that result in more than one) is produced.
Productivity modules can only be used to make intermediate products. These are products that cannot directly be placed, but are used in other recipes. Examples include circuits, science packs and engine units.
Advantages & Disadvantages:
- Creates an additional free item occasionally.
- Increases energy use per cycle.
- Increases pollution generated.
- Slows the machine.