# Step 8: Review the cost estimation
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Review and refine the cost estimation again. Additionally, it's a good practice to validate it with business stakeholders and get approval to move to the next step.



## Objectives
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+ Define the capacity model, and estimate DynamoDB costs to refine the cost estimation from [step 2](step2-hierarchical-model.md).
+ Get the final financial approval from the business analyst and stakeholders.

## Process
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+ Database engineer identifies the data volume estimate.
+ Database engineer identifies the data transfer requirements.
+ Database engineer defines the required read and write capacity units.
+ Business analyst decides between [on-demand and provisioned capacity models](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.ReadWriteCapacityMode.html).
+ Database engineer identifies the need for [DynamoDB auto scaling](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/AutoScaling.html).
+ Database engineer inputs the parameters in the AWS Pricing Calculator.
+ Database engineer presents the final price estimation to business stakeholders.
+ Business analyst and stakeholders approve or reject the solution.