System Security Plan (SSP) Development
The System Security Plan is the document the entire authorization stands on. AvoraTech develops SSPs that describe the system as it actually runs, map cleanly to the NIST 800-53 Rev 5 baseline, and give assessors and the Authorizing Official a clear, verifiable picture. A strong SSP shortens the assessment. A weak one generates findings before testing even starts.
Why the SSP Carries So Much Weight
Everything downstream references the SSP. Assessors test controls against the narratives in it. The Security Assessment Report records how the implementation held up. The POA&M tracks the gaps. The Authorizing Official reads it to understand what they are accepting risk on. When the SSP is accurate and well organized, the rest of the package falls into place. When it drifts from reality, the whole authorization inherits that drift.
What We Build Into an SSP
- System description and categorization: What the system does, the data it handles, and its FIPS 199 impact level.
- Authorization boundary and architecture: A precise definition of what is in scope, with the diagrams and data flows to back it.
- Control implementation narratives: For each applicable control, a description of how it is satisfied that an assessor can verify against the running system.
- Inheritance and shared responsibility mapping: Clear statements of which controls are inherited, shared, or fully owned by the system.
- Supporting plan references: Ties to the contingency plan, incident response plan, configuration management plan, and continuous monitoring strategy.
Narratives That Match the System
The single most valuable thing we bring to an SSP is the discipline of writing narratives that an assessor can confirm. That means describing the actual configuration, naming the mechanism that satisfies the control, and being honest about partial implementations so they land in the POA&M rather than ambushing you during assessment. Narratives that restate the control language or describe an aspirational state are the fastest route to a long findings list.
Boundary and Inheritance Done Carefully
A loosely drawn authorization boundary is one of the most expensive mistakes in the whole process, because it expands what gets assessed and invites disputes late. We define the boundary deliberately and document inheritance precisely, so a cloud-hosted system gets proper credit for the controls its platform provides and the assessment focuses on what the system genuinely owns.
Built for FISMA, FedRAMP, and RMF
Whether the SSP supports a FISMA authorization, a FedRAMP package, or a DoD effort aligned to CMMC, it rests on the same NIST 800-53 foundation. We develop SSPs that fit the specific format and expectations of your authorization path while keeping the underlying control evidence reusable across whatever comes next.
Frequently Asked Questions
What is a System Security Plan?
A System Security Plan, or SSP, is the document that describes a system, its authorization boundary, and how each applicable NIST 800-53 control is implemented. It is the foundation of an authorization package. Assessors test against it and the Authorizing Official relies on it, so the SSP has to describe the system that actually exists, not an idealized version.
What goes into an SSP?
An SSP typically includes the system description and categorization, the authorization boundary and architecture, data flows, the control implementation narratives for each applicable control, roles and responsibilities, and references to supporting plans such as the contingency and incident response plans. The control narratives are the heart of it.
What makes an SSP fail assessment?
The most common failure is drift between the narrative and the running system. A control narrative that describes a setting that was never enabled, or a boundary that does not match the architecture, generates findings immediately. SSPs also fail when narratives are vague, restate the control language instead of describing the implementation, or leave inherited controls unclear.
What is control inheritance in an SSP?
Inheritance is when a system relies on controls provided by an underlying platform or provider rather than implementing them itself. A cloud-hosted system, for example, may inherit physical and environmental controls from the cloud provider. The SSP has to state clearly which controls are inherited, which are shared, and which the system implements directly.
Related Services
Tell us about your system and target authorization. We will scope the SSP work to match.
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