I can answer primarily for Uprising, but Retribution appears similar.
Retribution scoreboard screenshot:
Points are awarded for four categories:
- Kill score
- Each enemy killed awards a static amount of points
- "Objective Bonus" / Progression
- Each section of the mission completed awards a static amount of points
- "Survival Bonus"
- After each section of the mission, a bonus is given depending on the number of incaps incurred in the completed section
- "Time Bonus"
- After each section of the mission, a bonus is given depending on the time taken in completing the section.
On Uprising, these scores were completely shared between team members. One player dying would drop the survival bonus for all players.
Some other notes about the score:
- One player dying completely removed the survival bonus for a section--it was all or nothing
- Time bonus has a maximum amount of each section, and linearly degrades if you take longer than some amount of time.
- Kill score is capped per-section to some maximum amount. That is, you can sit in a section and farm kill score, but it's not infinite, and you'll lose out on time bonus.