How can scrum master find technique for effective PB management
Where does the knowledge come from, according to the Scrum Guide?
Too broad question, Parthima.
Can you narrow it down a bit or provide a context, please?
You can start with the following
Business value that the story brings in
Customer/clients feedback
Support Desk/Product Support feedback
I am not sure what aspect you are trying to manage, but I would suggest on prioritizing it first so that the focus will be limited to the highest priority items in the backlog. For prioritization there are several techniques. I prefer the buy you feature, 100 point method which will force the stakeholders to limit their ask for the most wanted functionality. There are articles for both techniques, but in layman terms the below will give an idea of how to do this.
1) Buy a feature is a technique where the team puts a price tag against each feature based on how complex and much effort it would take to build that feature, Basically their estimation is represented as the cost on each feature. Now the stakeholders are all given equal amount of money (enough to buy at least the highest feature). I usually limit it so that the best thing that all want will come out ! you can use fake money or even poker chips and make it a fun game :)
2) 100 point method is similar but less fun. Each person can use 100 points to value their features. But here we are only looking at what they want and not how much effort it takes. For example if I have 100 points and I like one feature the most (feature A) and just one more (feature B) which I can live without I would use 90 points for A and the rest for B. Using this method the most valuable feature from the stakeholder comes to top, but the real value is the business value divided by the effort. If the effort for this feature is so much high than the next best feature that is fairly easy to do using the bang for buck method the second one should be more viable to do.
3) Find more about bang for the buck here - https://www.innovationgames.com/4454-2/ but its not as engaging and entertaining as 1) in my opinion.
But my personal favourite is Buy a feature as it addresses both sides of the coin, both the business value and the effort it takes to do it.