The Full Form of SRR is‍ System Requirements Review.

The SRR is conducted to ascertain progress in defining system technical
requirements. It determines the direction and progress of the systems
engineering effort and the degree of convergence upon a balanced and
complete configuration baseline. It is normally held during the Technology
Development phase, but it may be repeated after the start of Engineering
and Manufacturing Development (EMD) to clarify the contractor’s
understanding of redefined or new user requirements.

The SRR is a technical review to ensure that the system under review can
proceed into initial systems development, and that all system requirements
and performance requirements derived from the Initial Capabilities
Document or draft Capability Development Document are defined and
testable, and are consistent with cost, schedule, risk, technology readiness,
and other system constraints. Generally this review assesses the system
requirements as captured in the system specification, and ensures that the
system requirements are consistent with the approved materiel solution
(including its support concept) as well as available technologies resulting
from the prototyping effort.

Of critical importance to this review is an understanding of the program
technical risks inherent in the system specification and in the EMD phase
SEP. Determining an acceptable level of risk is essential to a successful
review.
Completion of the SRR should provide the following:
• An approved system specification with sufficiently conservative
requirements to provide for design trade space for the EMD phase,
• A preliminary allocation of system requirements to hardware, human,
and software subsystems,
• A preliminary Identification of all software components (tactical,
support, deliverable, non-deliverable, etc.),
• A comprehensive risk assessment for EMD,
• An approved EMD phase SEP that addresses cost and critical path
drivers.
• An approved Life Cycle Sustainment Plan

During the SRR, the systems requirements are evaluated to determine
whether they are fully defined and consistent with the mature technology
solution, and whether traceability of systems requirements to the Initial
Capabilities Document or draft Capability Development Document is
maintained. A successful review is predicated on the IPT’s determination that
the system requirements, approved materiel solution, available technology,
and program resources (funding, schedule, staffing, and processes) form a
satisfactory basis for proceeding into the EMD phase