ANSI AAMI SW91-2018 PDF

Full title and description

ANSI/AAMI SW91:2018 — Classification of defects in health software. AAMI consensus standard that defines a defect taxonomy and common terminology for classifying software defects that occur in health and medical‑device related software.

Abstract

This standard provides a neutral, lifecycle‑wide taxonomy for classifying defects in health software (including third‑party software, medical device software, test and manufacturing software). It defines defect categories and codes, illustrates use cases and examples in annexes, and is intended to support consistent defect reporting, root‑cause analysis, defect trending and industry‑wide aggregation of defect data to improve software quality and reliability.

General information

• Status: Current (ANSI/AAMI SW91:2018 edition; no amendment listed as of February 19, 2026)
• Publication date: 2018 (published Oct–Nov 2018; FDA recognition: January 14, 2019)
• Publisher: Association for the Advancement of Medical Instrumentation (AAMI) / ANSI designation
• ICS / categories: Health care technology; software quality and software engineering; medical device software / software and informatics
• Edition / version: 2018 edition (ANSI/AAMI SW91:2018)
• Number of pages: Approximately 68–76 pages depending on format (PDF/hardcopy)

Scope

Defines a defect classification system (taxonomy) that can be applied to types and root causes of defects across the software development lifecycle for health‑related software. The taxonomy is intentionally neutral with respect to programming language, development methodology, product, intended use, risk classification or regulatory status. It does not prescribe severity scoring, risk management methods, or corrective action procedures; rather it provides a common language and code set for describing defects and their technical/process root causes.

Key topics and requirements

• Standardized defect taxonomy covering planning through deployment phases (includes an indexed list of defect types and codes).
• Definitions and terminology for consistent defect classification across organisations and tools.
• Annexes with use cases, worked examples and mapping illustrations to show practical application of the taxonomy.
• Guidance on applying the taxonomy to third‑party software, test software and manufacturing/automation software used in healthcare.
• Focus on technical and process root causes (supports root cause analysis and defect trending; does not assign clinical severity by itself).
• Support for aggregation of defect data to inform quality improvement, testing strategy and supplier management.

Typical use and users

Used by medical‑device and health‑software manufacturers, software developers, verification & validation teams, quality assurance, clinical engineering, regulatory affairs, risk managers, suppliers and auditors. Commonly applied in defect tracking, post‑market surveillance analysis, root‑cause investigations, test planning and to harmonize reporting across organisations or suppliers.

Related standards

Commonly used alongside IEC 62304 (medical device software lifecycle), ISO 14971 (risk management for medical devices), ISO/IEC/IEEE 29119 (software testing), AAMI technical reports and guidance (e.g., AAMI TIRs on security/risk) and FDA guidance on software and SaMD. The standard is recognized by FDA as a consensus standard (recognition date: January 14, 2019).

Keywords

defect taxonomy, health software, medical device software, software defects, root cause classification, defect coding, software quality, AAMI, ANSI, software testing, post‑market surveillance

FAQ

Q: What is this standard?

A: ANSI/AAMI SW91:2018 is a consensus standard that defines a structured taxonomy and common terminology for classifying defects found in health‑related software.

Q: What does it cover?

A: It covers defect types and root causes across the software lifecycle (planning, design, implementation, testing, integration, release and maintenance) and provides annexes with examples and use cases. It does not prescribe risk scoring or corrective actions.

Q: Who typically uses it?

A: Software developers, QA/verification teams, biomedical and clinical engineers, regulatory and quality professionals, suppliers, and organisations performing post‑market surveillance and root‑cause analysis in the healthcare sector.

Q: Is it current or superseded?

A: The document is the 2018 edition (ANSI/AAMI SW91:2018) and was recognized by the U.S. FDA on January 14, 2019. No superseding revision or formal amendment was listed as of February 19, 2026; organisations should check the publisher for any updates before use.

Q: Is it part of a series?

A: It is a standalone AAMI consensus standard but is typically used in conjunction with other medical‑device and software standards (for example IEC 62304, ISO 14971, ISO/IEC/IEEE 29119 and related AAMI TIRs and guidance documents).

Q: What are the key keywords?

A: Defect taxonomy; health software; software defects; root cause; classification; AAMI; ANSI; software quality; medical device software.