What does RICE stand for?
It's an acronym for the following:
R: Reach
I: Impact
C: Confidence
E: Effort
What is it used for?
Companies usually have hundreds of solutions they can implement at any given point in time. But they only have the resources to implement a subset of these.
This is where prioritization comes into the picture. They weigh these solutions across different parameters and attach a priority number for each solution.
RICE is just one of the frameworks used for this.
Deep dive into the factors
Reach
This factor measures how many users will get affected by the solution. A higher rating is given to solutions that affect more users and vice versa. It is fairly straightforward to understand.
Impact
All solutions try to make some pain point a user is facing less painful. That said, this metric measures a combination of the following things:
How painful is the pain point to begin with?
By how much does the solution ease the pain? i.e. what impact does the solution have on the pain?
Confidence
This is one of the more subjective factors.
Product managers over time, get better at understanding their user's pain points and understanding what type of solutions have a higher chance of working. This is because their mental models are constantly being updated based on feedback from the users.
This measures the confidence they have in the solution. It is essentially their intuition.
Effort
This is the net effort required to implement the solution.
For hardware products, this might be the cost of materials, time taken to produce, etc.
For software products, this would likely be measured in terms of the number of hours required by developers, and designers to implement.
Conclusion
At the end of the day, these frameworks are just guidelines that can be considered and each company uses different ways of prioritizing their solutions.