The Measurement Methodology Behind Software Gauge

Functional Size: What the Software Does, Not How It Is Built

Most vendor estimates measure effort — hours, sprints, team-weeks. These numbers are internal to the vendor and impossible to verify independently.

Functional size measurement takes a different approach. It measures what the software is required to do: the number of distinct data movements it must process. This measurement is independent of the technology used, the team size, the development methodology, and the vendor's internal practices.

Software Gauge measures functional size using COSMIC Function Points (CFPs), defined in ISO 19761:2011.

COSMIC Function Points (ISO 19761)

COSMIC Function Points are a unit of software functional size, standardized by the International Organization for Standardization as ISO/IEC 19761:2011.

A COSMIC Function Point measures a single data movement — one of four types:

Each data movement counts as exactly 1 CFP. The total CFP count for a software system is the sum of all data movements across all functional processes. This makes COSMIC sizing objective, consistent, and verifiable — the same requirements document, sized by two different analysts following the ISO 19761 standard, should produce the same CFP count within a small margin of variance.

How Software Gauge Applies COSMIC to Your Requirements

When you upload a requirements document, Software Gauge performs the following steps:

1. 1

   Identify functional processes

   Distinct units of work that the software must perform in response to a triggering event — a user action, a system event, or a data arrival.

2. 2

   Map data movements

   For each functional process, the analysis identifies all Entries, Exits, Reads, and Writes.

3. 3

   Count CFPs

   Sum the data movements to produce a total COSMIC Function Point count for the scope described in your requirements.

The CFP count is your functional size — a vendor-neutral measure of scope that any qualified software vendor can price against.

Benchmarking Against the ISBSG Database

Knowing the functional size of your project is the first step. The second is translating that size into a cost benchmark.

Software Gauge uses productivity and rate data from the ISBSG (International Software Benchmarking Standards Group) database — a repository of performance data collected from over 12,500 real software projects globally, across industries, geographies, and development approaches.

For a given CFP count and project type, the ISBSG database provides three benchmark tiers:

These benchmarks reflect real, completed projects — not vendor quotes or theoretical rates.

Cost Driver Adjustments

Raw CFP counts are adjusted for project-specific cost drivers that affect delivery effort. Software Gauge asks ten structured questions covering: system integration complexity, compliance and security requirements, expected transaction volume and performance, delivery timeframe constraints, and requirements completeness.

Each answer applies a calibrated multiplier to the base estimate, consistent with recognized industry cost-driver frameworks.