Overview
ISO/IEC 25986:2026 introduces the Easy Functional Sizing (EFS) method, a standardized approach for measuring the functional size of software systems. Developed by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC), this standard simplifies the NESMA Functional Size Measurement method. EFS addresses the growing need for clarity and ease of use in software size measurement, especially in Agile and DevOps environments.
EFS is designed for anyone involved in software estimation, project management, or software quality assurance. By providing objective, repeatable rules for functional size measurement, the standard helps organizations deliver reliable project estimates, compare productivity, and support process improvements.
Key Topics
- Purpose and Principles: EFS provides a simplified framework for measuring the functional size of information systems, focusing on what the system delivers, rather than how it is technically implemented.
- Core Components: EFS categorizes user-recognizable functionality into three types:
- Logical Files (LF): Logical groups of permanent data used or maintained by the system.
- External Inputs (EI): Functions that modify data within logical files (add, modify, delete).
- External Outputs (EO): Functions that present data from the system to users or external systems.
- Points System: Each identified component receives a set value in function points (LF = 7, EI = 4, EO = 5). The sum represents the functional size of the software.
- User and System Boundaries: Clear definitions of what constitutes a user and the system boundary provide a consistent scope, ensuring accurate and repeatable measurements.
- Conformity: EFS aligns with ISO/IEC 14143-1:2007, ensuring comparability with established measurement practices such as those in ISO/IEC 24570:2018.
Applications
Practical Value of EFS:
- Agile and DevOps: EFS allows teams to quickly estimate and track the functional size of increments or sprints, supporting iterative development without complex overhead.
- Project Estimation: By measuring the functional size at any project phase, organizations can reliably forecast budgets, team size, and delivery timelines.
- Software Procurement: EFS provides a neutral, vendor-independent metric for scoping contracts and functional enhancements, supporting transparency with stakeholders.
- Performance Metrics: The function point count serves as a baseline for productivity analysis, benchmarking, and tracking process improvement across software projects.
- Change Management: Functional enhancement, such as adding, changing, or removing features, can be quantitatively tracked and managed using EFS.
Target Audience:
- Software developers
- Project and product managers
- Estimators and contract managers
- Quality assurance professionals
- Business analysts
Related Standards
For organizations seeking a broader view on software functional size measurement, consider referencing:
- ISO/IEC 14143-1:2007: Defines the general concepts and framework for functional size measurement.
- ISO/IEC 24570:2018: Covers the NESMA Function Point Analysis method at a higher level of granularity.
- ISO/IEC TR 14143-5:2004: Offers guidance on the application of functional size measurement across various domains.
Summary
Adopting ISO/IEC 25986:2026 and the Easy Functional Sizing (EFS) method empowers organizations to achieve consistent, efficient, and objective software size measurement. This practical approach aligns with industry best practices and adapts seamlessly to both traditional and modern development environments, supporting cost-effective and high-quality software delivery. For additional detail, supporting documentation, and industry examples, visit the NESMA website or related ISO resources.
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