Software Development for Medical Devices in Regulated Environments
Introduction
As a software developer in MedTech, you face a stark contrast between conventional software engineering and regulated medical device development. While the tech industry celebrates rapid iteration and “move fast and break things,” medical device development prioritizes patient safety, regulatory compliance, and exhaustive documentation. These aren’t optional as they are required before your software can reach a single patient. The challenge extends beyond writing functional code to simultaneously proving to regulators that it’s safe, effective, and secure.
Internationally-recognized standards, primarily IEC 62304, ISO 14971, and ISO 13485 establish lifecycle processes designed to ensure patient safety. Understanding these requirements is essential whether you’re developing embedded firmware, standalone Software as a Medical Device (SaMD), or software used in a quality system.
IEC 62304 and Risk Based Development
IEC 62304 is the internationally recognized standard for medical device software development. The standard uses a risk based classification system that categorizes software into three safety classes: Class A (no injury possible), Class B (non-serious injury possible), and Class C (death or serious injury possible). The rigor of development processes, documentation requirements, and testing activities increases with the software safety class.
This risk based approach, integrated with ISO 14971 risk management, ensures that development efforts are proportionate to patient harm. The FDA recognizes IEC 62304 as an acceptable framework for demonstrating compliance with software lifecycle requirements..
Verification and Validation
Software verification and validation (V&V) in regulated environments goes beyond executing software testing. As described in ISO 13485, the tools and infrastructure used to develop the software itself and those tools and processes used to get the software into production must also be validated.
Validation must follow documented protocols with predefined acceptance criteria established before testing even begins. Requirements documentation forms the foundation to determine what testing is needed. User Requirements Documentation must specify intended use, operating environment, performance requirements, and safety related functions. Software Requirements Specification must document all inputs, outputs, functions, interfaces, error handling, and safety related features. The design file must include testing protocols with traceability between requirements and tests, clear acceptance criteria, and results with appropriate evidence to demonstrate safety, security, and effectiveness.
The device manufacturer retains ultimate responsibility for validation even when using third party contractors or testing laboratories.
Configuration Management and Change Control
Configuration management is one of the most critical requirements in IEC 62304 and ISO 13485. Configuration items must be placed under documented configuration management control before they are verified (applicable to Class B and C software). This includes source code, requirements documents, design specifications, test plans, development tools and settings, and SOUP (Software of Unknown Provenance) components.
Configuration management intersects with change control processes mandated by IEC 62304 and ISO 13485. Every change to a configuration item requires identification, risk analysis, verification and validation, approval before implementation, impact assessment on already delivered products, documentation, and follow up effectiveness assessment. Organizations must evaluate whether changes require new or revised regulatory applications.
SOUP and Third Party Software
Software of Unknown Provenance (SOUP) – software already developed and generally available, not developed specifically for the medical device, or developed without adequate records, presents unique validation challenges. Most medical device software incorporates SOUP components: operating systems, libraries, frameworks, commercial packages.
The device manufacturer is responsible for ensuring all software, including SOUP, performs as intended. This requires vendor assessment, auditing development methodologies when possible, and reviewing validation documentation. When vendor documentation isn’t available, manufacturers must perform sufficient black box testing. The FDA guidance provides clear expectations when it comes to SOUP, which they refer to as off-the-shelf software.
Software Maintenance and Post Market Surveillance
IEC 62304 mandates maintenance processes that extend throughout the product lifecycle. Section 6.1 requires a software maintenance plan addressing feedback management, problem resolution, and modification control.
Every modification requires analysis of effects on performance, safety, and regulatory clearance. Manufacturers must verify through trace or regression analysis that risk control measures aren’t adversely affected and that modified software doesn’t introduce new hazards. Safety related problem reports must be addressed and possibly even reported to regulatory authorities. The maintenance process operates within configuration management and risk management frameworks and changes must be controlled, documented, and tested with the same rigor as initial development.
Cybersecurity: Secure by Design
Cybersecurity has moved from peripheral concern to a central requirement. Regulatory authorities worldwide including the FDA and European MDCG expect manufacturers to demonstrate cybersecurity risk management throughout the device’s lifetime.
Manufacturers must adopt a “secure by design” approach, building security into devices from the earliest stages. This includes implementing secure coding frameworks such as those mentioned in the FDA’s cybersecurity guidance and IEC 81001-5-1.
Baseline medical device standards include ISO 14971, ISO 13485, IEC 62304, and IEC 60601 series. However, these standards do not address the cybersecurity requirements now mandated by regulators. The widely recognized standard for cybersecurity in medical devices is ISO 81001-5-1. Furthermore, the information security controls within ISO 27001 are becoming increasingly mandated (e.g., NIS2) – indicating that cybersecurity needs to be managed throughout the organization’s day-to-day processes and not just during medical device design and development.
Practical Implementation
Key practices for successful implementation:
Automate as much as possible: Automation across tooling like issue tracking, requirements management, and traceability systems helps ensure that every requirement, change, and defect is consistently linked, tracked, and auditable throughout the device’s lifecycle. By reducing manual processes and enforcing structured workflows, these tools minimize the risk of missed requirements, incomplete verification, or undocumented changes, while making it much easier to demonstrate compliance and maintain configuration control over time.
Start risk management early: this ensures that safety and cybersecurity considerations directly shape software requirements, architecture, and design decisions from the outset, rather than being retrofitted later. Early identification and classification of risks allows teams to apply the appropriate level of rigor (e.g., as appropriate for the software safety class), reducing costly redesigns and helping ensure that hazards are systematically mitigated, verified, and traceable throughout the entire lifecycle.
Lifecycle cost planning: Budget for ongoing maintenance, post market surveillance, cybersecurity monitoring, SOUP updates, and re-validation. Regulatory compliance isn’t a one time event but continuous commitment.
Early regulatory engagement: The regulatory pathway and targeted jurisdictions should inform development planning from the outset.
Conclusion
Software development for medical devices requires mastery of both software engineering and regulatory compliance. The requirements exist because patient safety depends on them.
Organizations that view regulatory requirements as compliance burdens miss the value: these processes create better software. Risk based development focuses engineering effort where it matters. Documentation enables effective maintenance and knowledge transfer. Verification prevents costly post market corrections.
The path forward requires commitment to building quality and safety into development from the earliest stages, where regulatory compliance and engineering excellence work together to protect patients while enabling innovation.
