ISO/IEC/IEEE 32430:2025
(Main)Software engineering — Software non-functional size measurement
Software engineering — Software non-functional size measurement
This document defines a method for measuring the non-functional size of the software. It complements ISO/IEC 20926:2009, which defines a method for measuring the functional size of the software. This document also describes the complementarity of functional and non-functional sizes, so that deriving the sizes from the functional and the non-functional requirements does not result in duplication in the distinct functional and non-functional sizes. In general, there are many types of non-functional requirements. Moreover, non-functional requirements and their classification evolve over time as the technology advances. This document does not intend to define the type of NFR for a given context. Users can choose ISO 25010 or any other standard for the definition of NFR. It is assumed that users size the NFR based on the definitions they use. This document covers a subset of non-functional requirements. It is expected that, with time, the state of the art can improve and that potential future versions of this document can define an extended coverage. The ultimate goal is a version that, together with ISO/IEC 20926:2009, covers every aspect that can be required of any prospective piece of software, including aspects such as process and project directives that are hard or impossible to trace to the software's algorithm or data. The combination of functional and non-functional sizes would then correspond to the total size necessary to bring the software into existence. Estimating the cost, effort and duration of the implementation of the NFR is outside the scope of this document.
Ingénierie du logiciel — Norme pour la quantification des caractéristiques non fonctionnelles des logiciels
General Information
Relations
Standards Content (Sample)
International
Standard
ISO/IEC/IEEE 32430
Second edition
Software engineering — Software
2025-02
non-functional size measurement
Ingénierie du logiciel — Norme pour la quantification des
caractéristiques non fonctionnelles des logiciels
Reference number
© IEEE 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO or IEEE at the
respective address below or ISO’s member body in the country of the requester.
Institute of Electrical and Electronics Engineers, Inc
3 Park Avenue, New York
NY 10016-5997, USA
Email: stds.ipr@ieee.org
Website: www.ieee.org
Published in Switzerland
© IEEE 2025 – All rights reserved
ii
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
1.1 Overview .1
1.2 Purpose .1
1.3 Word usage .1
2 Normative references . 2
3 Terms, definitions and abbreviated terms . 2
3.1 Terms and definitions .2
3.2 Abbreviated terms .8
4 Introductory information . 8
4.1 User requirements for a system .8
4.2 Non-Functional Size Measurement (NFSM) introduction .9
4.3 Software-intensive system and software product .10
4.4 Software domains . .10
4.5 The relations between non-functional requirements (NFR) and functional user
requirements (FUR) .10
4.5.1 Non-functional requirements .10
4.5.2 The relations between NFR and SNAP sub-categories.10
4.6 Current classification and Future evolution of NFR . 13
4.6.1 The challenge . 13
4.6.2 Current classification of NFR . 13
4.6.3 Sizing quality-in-use requirements . 13
4.7 Objectives and benefits .14
4.7.1 Objectives .14
4.7.2 Benefits .14
5 Non-functional size: Categories and sub-categories .15
5.1 Category 1: Data operations . 15
5.1.1 Sub-category 1.1: Data entry validation . 15
5.1.2 Sub-category 1.2: Logical and mathematical operations .16
5.1.3 Sub-category 1.3: Data formatting .18
5.1.4 Sub-category 1.4: Internal data movements .19
5.1.5 Sub-category 1.5: Delivering added value to users by data configuration .21
5.2 Category 2: Interface design . . 23
5.2.1 Sub-category 2.1—User interfaces . 23
5.2.2 Sub-category 2.2—Help methods . 25
5.2.3 Sub-category 2.3—Multiple input methods . 28
5.2.4 Sub-category 2.4—Multiple output methods . 29
5.3 Category 3: Technical environment .31
5.3.1 Sub-category 3.1: Multiple platforms .31
5.3.2 Sub-category 3.2: Database technology . 33
5.3.3 Sub-category 3.3: Batch processes . 35
5.4 Category 4: Architecture . 36
5.4.1 Sub-category 4.1: Component-based software . 36
5.4.2 Sub-category 4.2—Multiple input/output interfaces .37
5.5 Sizing code data .41
5.5.1 Code data characteristics .41
5.5.2 Handling code data from non-functional sizing perspective .42
5.5.3 How code data is sized using SNAP .42
6 The sizing process .43
6.1 Introduction .43
6.2 The timing of the non-functional sizing . 44
6.3 Non-functional sizing and FSM . 44
© IEEE 2025 – All rights reserved
iii
6.4 Steps to determine the non-functional size .45
6.4.1 Step 1: Gather available documentation .45
6.4.2 Step 2: Determine the sizing purpose, type, scope, boundary, and partition .45
6.4.3 Step 3: Identify the NFR . 48
6.4.4 Step 4: Associate NFR with sub-categories and identify the SCU. 49
6.4.5 Step 5: Determine the SNAP size for each sub-category . 49
6.4.6 Step 6: Calculate the non-functional size . 49
6.4.7 Step 7: Document and report . 49
6.5 Calculating the non-functional size . 50
6.5.1 Formula approach . 50
6.5.2 Determine the non-functional size of each sub-category . 50
6.5.3 Determine the non-functional size of a development project . 50
6.5.4 Determine the non-functional size of an enhancement project . 50
7 Complementarity of the functional and the non-functional sizes .53
7.1 General . 53
7.2 Requirements involving functional and non-functional requirements . 53
7.2.1 Sub-category 1.1 data entry validation . 53
7.2.2 Sub-category 1.2 logical and mathematical operations . 54
7.2.3 Sub-category 1.3 data formatting . 55
7.2.4 Sub-category 1.4 internal data movements . 56
7.2.5 Sub-category 1.5 delivering added value to users by data configuration . 56
7.2.6 Sub-category 2.1 user interfaces.57
7.2.7 Sub-category 2.2 help methods . 58
7.2.8 Sub-category 2.3 multiple input methods . 58
7.2.9 Sub-category 2.4 multiple output methods .59
7.2.10 Sub-category 3.1 multi
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.