What is a Secure Software Development Lifecycle (SSDLC)?
A Secure Software Development Lifecycle (SSDLC) is an approach that embeds security practices, requirements, and accountability across software planning, design, implementation, build, testing, release, operation, and maintenance. It shifts security from a late test or approval activity into repeatable engineering work. The NIST Secure Software Development Framework (SSDF) is a widely used framework for organizing fundamental secure development practices; it can inform an SSDLC, but an SSDLC is the organization’s operating model rather than a single prescribed toolchain or checklist.
Its scope includes decisions made before code is written, such as security requirements, architecture, and threat-informed design, as well as evidence generated by build, test, release, and maintenance activities.
What is a Secure Software Development Lifecycle (SSDLC) used for?
An SSDLC is used to reduce avoidable security defects and delivery risk through practices such as secure coding, dependency management, build integrity, testing, vulnerability handling, and release governance. The implementation should fit the organization’s architecture, development model, risk tolerance, and supplier relationships.
Leaders should establish accountable owners, measurable control evidence, exception paths, and feedback loops from production issues to engineering practice. Automating checks can improve consistency, but automation does not replace design judgment, remediation capacity, or clear decisions when delivery pressure conflicts with documented security requirements.
