How is value (in a scale of 1-10) assigned in Estimate of Value calculated (For instance as shown in figure below) in Product Backlog in Scrum Process?
Scrum doesn't define the concept of "value" estimates. Estimation usually focuses on some combination of complexity, effort and risk. In the example you have given it looks like modified Fibonacci estimates have been used for the effort estimate column but I can't tell what the Value column means. Maybe something like function points (see ifpug.org).
It doesn't matter how you prioritize Product Backlog items so long as you:
- achieve general consenses, and
- ensure everyone understands that when "everything is a top priority" then nothing is.
The implementation details don't actually matter. Whats essential is that the majority of stakeholders feel comfortable with the process.
Ways to Estimate Relative Value
There is no canonical answer to this question. "Value" is going to be project-specific, and based on the product or service you are delivering, the market you're targeting, and various business priorities and resource constraints.
There are certainly some techniques that you might use, but this is neither meant to be exhaustive nor canonical. Mountain Goat Software, from the same Mike Cohn who wrote a number of books on Scrum and user stories, provides some tools on his website such as:
- Project Success Sliders
- Theme Screening
- Relative Weighting
- Theme Scoring
In general, the idea is that you build consensus with stakeholders around what is valuable to their roles, responsibilities, or business domains. Then the Product Owner can prioritize the Product Backlog in a way that most stakeholders will at least support even if they don't necessarily fully agree on the final rankings.