Henry is the business analyst for his organization.

The all out approach is a timeboxing or budgeting technique that involves excluding all the requirements for a start and then including the ones that can be implemented within the constrained time or budget. Henry is using this approach by removing the requirements from the allowed list until he meets the budget limit. This is different from the all in approach, which involves including all the requirements necessary for the solution and then removing or postponing the ones that will cause the project to exceed the deadline or budget. The parametric approach is a cost estimation technique that uses statistical relationships between historical data and other variables. The selective approach is a prioritization technique that involves ranking the requirements based on their value and urgency. References:

CBAP Certification Study Guide v3.0, p. 223

BABOK Guide v3, p. 156