ISO/IEC 21031:2024 情報技術 | ページ 2

Foreword

ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work.

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ISO and IEC draw attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO and IEC take no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO and IEC had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents and https://patents.iec.ch . ISO and IEC shall not be held responsible for identifying any or all such patent rights.

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For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html . In the IEC, see www.iec.ch/understanding-standards .

This document was prepared by the Linux Foundation (as Software Carbon Intensity (SCI) Specification, v.1.0) and drafted in accordance with its editorial rules. It was adopted, under the JTC 1 PAS procedure, by Joint Technical Committee ISO/IEC JTC 1, Information technology.

Introduction

“If you can't measure it, you can't improve it.” – Peter Drucker

Software systems cause emissions through the hardware that they operate on, both through the energy that the physical hardware consumes, and the emissions associated with manufacturing the hardware. This specification defines a methodology for calculating the rate of carbon emissions for a software system. The purpose is to help users and developers make informed choices about which tools, approaches, architectures, and services they use in the future. It is a score rather than a total; lower numbers are better than higher numbers, and reaching 0 is impossible. This specification is focused on helping users and developers understand how to improve software to reduce or avoid the creation of emissions.

Reducing an SCI score is only possible through the elimination of emissions. That can be achieved by modifying a software system to use less physical hardware, less energy, or consume lower-carbon energy sources. Neutralization or avoidance offsets do not reduce an SCI score (Clause 12). This makes the SCI an ideal strategy that organizations can adopt to meet climate targets focused on eliminating emissions, such as those specified by^[ 1 ^].

The SCI is for everyone. It is possible to calculate an SCI score for any software application, from a large, distributed cloud system to a small monolithic open source library, any on-premise application, or even a serverless function. The environment the product or service is running in can also vary; from personal computers, private data centers or a hyperscale cloud.

Software practitioners have a significant role to play in collectively reducing the SCI score during the design, development, and delivery of software applications. The following list provides some strategies that can be used to do this across different software roles:

• For a software programmer, this implies writing energy efficient code.
• For an AI/ML developer, it implies model optimization, using pre-trained models or leveraging optimized hardware for training.
• For a database engineer, this comprises choices like schema design, choice of storage, and query optimizations.
• For a DevOps practitioner, this requires creating a carbon-aware pipeline and considering when to schedule builds and leverage clean energy.
• For QA engineers, it involves creating energy efficient test automation and performance testing scripts across browsers and devices.
• For an architect, this implies choices like serverless or event driven architectures, infrastructure optimization, and design for carbon-aware systems.

The SCI encourages calculation using granular real-world data, which is challenging to obtain in some environments, particularly the public cloud. Access to the data needed for higher resolution calculations might not always be available.

Where this is the case, users of this specification are strongly advised to request such data from their suppliers (be they hardware, hosting, or other).

In situations where there is a lack of access, capability, or rights to the necessary real-world data, the SCI allows for data generated through modelling, using best estimates instead.

1 Scope

This specification describes a methodology for calculating the rate of carbon emissions for a software system; that is, its SCI score. The purpose of this score is to increase awareness and transparency of an application's sustainability credentials. The score will help software practitioners make better, evidence-based decisions during system design, development, and deployment, that will ultimately minimize carbon emissions. A reliable, consistent, fair and comparable measure allows targets to be defined during development and progress to be tracked.

2 Normative references

There are no normative references in this document.

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

Bibliography