Purpose and Scope This Guide presents the procedures to be employed by ABS in the review and surveys of computer-based control system software. The objective of this Guide is to reduce software-related incidents that could negatively affect the security@ safety and performance of such systems. Compliance with the procedures and criteria given in this Guide may result in the granting of the optional notation SSV to a vessel or offshore unit.This Guide emphasizes software verification of control systems and Hardware-In-the-Loop (HIL) testing. Criteria for the hardware@ Failure Mode and Effect Analysis (FMEA)@ and security of computer-based control systems are given in other ABS Rules and Guides@ such as the ABS Rules for Building and Classing Steel Vessels (Steel Vessel Rules)@ the ABS Guidance Notes on Failure Mode and Effects Analysis (FMEA) for Classification@ and applicable national and international standards. This Guide is applicable to standalone or integrated computer-based control systems. Such a computerbased control system can be installed on a ship@ offshore unit@ fixed or floating offshore installation@ or other type of facility. The computer-based system can be associated with a control system of any level of complexity@ including those used for propulsion and navigation. The procedures and criteria given in this Guide involve a number of parties concerned with software development and maintenance. These include Systems Providers (SP)@ Driller or Crew Organization (DCO)@ Ship Builder Integrator (SBI) or the Shipyard@ Verification and Validation Organizations (VV)@ Owner@ Sub-suppliers@ and Subcontractors involved in integrated system software development@ implementation@ operation@ and maintenance. Refer to Subsection 1/7 for definitions of these involved parties.