There is no one definitive answer to this question as it can depend on a variety of factors, including the particular system or framework being used. However, a few common methods for calculating a RICE score are described below.
One approach is to add up the values for each individual factor that make up the RICE score. For example, if you are using the RICE framework developed by the Agile software development community, the factors are:
R – Relative complexity or risk: How difficult is it to implement the proposed solution? A value of 1 indicates a very simple solution, while a value of 9 indicates a very complex solution.
I – Investment or importance: How important is it to implement the proposed solution? A value of 1 indicates a low-priority solution, while a value of 9 indicates a high-priority solution.
C – Customer or commercial value: What value will the proposed solution provide to customers or the business? A value of 1 indicates a low value, while a value of 9 indicates a high value.
E – Effort required: How much effort will be required to implement the proposed solution? A value of 1 indicates a very low level of effort, while a value of 9 indicates a very high level of effort.
Thus, the RICE score for a proposed solution with a relative complexity of 5, an investment of 8, a customer value of 7, and an effort required of 4 would be 5 + 8 + 7 + 4 = 24.
Another common approach is to multiply the values for each individual factor to arrive at the RICE score. So, using the same example as above, the RICE score would be 5 x 8 x 7 x 4 = 1,920.
Still another approach is to weight the values for each factor, depending on the relative importance of that factor. For example, if you feel that the customer value is twice as important as the other factors, you would weight it as follows:
Customer value: 7 x 2 = 14
Relative complexity: 5 x 1 = 5
Investment: 8 x 1 = 8
Effort required: 4 x 1 = 4
This would give a RICE score of 14 + 5 + 8 + 4 = 31.
As you can see, there is no one correct way to calculate a RICE score. It really depends on the particular system or framework you are using, as well as the relative importance of each individual factor.