Function Point Analysis (FPA) is the most suitable methodology for estimating the complexity of a large business application. FPA measures the functional size of software from the end-user's perspective by quantifying the application's functionality based on inputs, outputs, inquiries, internal logical files, and external interface files. This provides a standardized, technology-independent metric for size and complexity, which serves as a primary input for estimating development effort, cost, and duration. It is superior to other methods for business applications because it focuses on the logical requirements ("what" the system does) rather than the physical implementation ("how" it does it).

B. Work breakdown structure: This is a project management tool used to decompose a project into smaller, manageable tasks. It organizes work but does not estimate software complexity.
C. Critical path analysis: This is a project scheduling technique for determining the shortest possible project duration by identifying the longest sequence of dependent tasks. It is not an estimation method.
D. Software cost estimation: This is a broad discipline or outcome, not a specific methodology for estimating complexity. FPA is a specific technique used within software cost estimation.

1. ISACA CISA Review Manual

27th Edition. (2019). Domain 2: IT Governance and Management

Section 2.12 Project Management. The manual describes Function Point Analysis as a primary technique for estimating project size based on the number and complexity of inputs

outputs

and files

which is then used to predict effort and cost. It distinguishes this from scheduling techniques like Critical Path Method (CPM).

2. Abran

A.

& Robillard

P. N. (1996). "Function points analysis: An empirical study of its measurement processes." IEEE Transactions on Software Engineering

22(12)

895-910. This paper validates FPA as a standardized process for measuring the functional size of software

stating

"Function points are a measure of software size

from the end-user point of view" (p. 895).

3. International Function Point Users Group (IFPUG). (2010). Function Point Counting Practices Manual (CPM)

Release 4.3.1. Section 1.2

"What is Function Point Analysis?". This official guide defines FPA as a "standardized method for measuring the various functions of a software application" and explains its use in estimating project effort and cost.

4. Pressman

R. S.

& Maxim

B. R. (2020). Software Engineering: A Practitioner's Approach (9th ed.). McGraw-Hill. Chapter 26

"Project Planning

" discusses FPA as a method for "decomposition of function" to derive a quantitative measure of software size and complexity

which is then used in estimation models.