The FDA does not require any specific software development process to be used like the traditional waterfall process.
See IEC 62304 Software Development Life Cycle
Support for usage of any process is found in the FDA Guidance document “General Principles of Software Validation; Final Guidance for Industry and FDA Staff” (http://www.fda.gov/cdrh/comp/guidance/938.pdf)
Section 5.1 Software Life Cycle Activities states:
“This guidance does not recommend the use of any specific software life cycle model. Software developers should establish a software life cycle model that is appropriate for their product and organization. The software life cycle model that is selected should cover the software from its birth to its retirement.”
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“A life cycle model organizes these software development activities in various ways and provides a framework for monitoring and controlling the software development project. Several software life cycle models (e.g., waterfall, spiral, rapid prototyping, incremental development, etc.) are defined in FDA’s “Glossary of Computerized System and Software Development Terminology” (http://www.fda.gov/ora/inspect_ref/igs/gloss.html)
evolutionary development. See: spiral model.
spiral model. (IEEE) A model of the software development process in which the constituent activities, typically requirements analysis, preliminary and detailed design, coding, integration, and testing, are performed iteratively until the software is complete. Syn: evolutionary model. Contrast with incremental development; rapid prototyping; waterfall model.