ISA 62443 IC33 – All Questions and
Answers 100% Correct
What is the purpose of assigning a Target Security Level (SL-T) during the Assess
phase of ICS security implementation? - ANSWER-To determine the existing
vulnerabilities of the system.
What happens during the Develop & Implement phase of ICS security implementation?
- ANSWER-Countermeasures are implemented to meet the Target Security Level (SL-
T).
What is the primary goal of the Maintain phase in ICS security implementation? -
ANSWER-To ensure the Achieved Security Level (SL-A) is equal to or better than the
Target Security Level (SL-T).*
What is phase 1 of the IACS Cybersecurity Life Cycle? - ANSWER-Assess
What is phase 2 of the IACS Cybersecurity Life Cycle? - ANSWER-Develop &
Implement
What is phase 3 of the IACS Cybersecurity Life Cycle? - ANSWER-Maintain phase
What is step 1 of the IACS Cybersecurity Life Cycle (Assess Phase)? - ANSWER-High-
Level Cyber Risk Assessment
What is step 2 of the IACS Cybersecurity Life Cycle (Assess Phase)? - ANSWER-
Allocation of IACS Assets to Security Zones or Conduits
What is step 3 of the IACS Cybersecurity Life Cycle (Assess Phase)? - ANSWER-Detail
Cyber Risk Assessment
What is step 4 of the IACS Cybersecurity Life Cycle (Develop & Implement Phase)? -
ANSWER-Cybersecurity Requirements Specification
What is step 5 of the IACS Cybersecurity Life Cycle (Develop & Implement Phase)? -
ANSWER-Design and engineering of Cybersecurity countermeasures
What is step 6 of the IACS Cybersecurity Life Cycle (Develop & Implement Phase)? -
ANSWER-Installation, commissioning and validation of Cybersecurity countermeasures
What is step 7 of the IACS Cybersecurity Life Cycle (Maintain)? - ANSWER-
Cybersecurity Maintenance, Monitoring and Management of Change
,What is step 8 of the IACS Cybersecurity Life Cycle (Maintain)? - ANSWER-Cyber
Incident Response & Recovery
What are the continuous processes activities of the IACS Cybersecurity Life Cycle? -
ANSWER-Cybersecurity Management System: Policies, Procedures, Training &
Awareness, Periodic Cybersecurity Audits
What must be done before an assessment can be started? - ANSWER-Create a Project
Plan
ID Steps of the Project to perform the assessment
ID the System Under Assessment
System Under Consideration (SUC) - ANSWER-The system or systems within an
Industrial Automation and Control System environment that are being evaluated or
designed for security enhancements.
System Under Assessment (SUA) - ANSWER-The system that is being evaluated for
compliance with standards.
What are some required information gathering items before the assessment can begin?
- ANSWER-Goals of the Assessment
IACS asset inventory
Understanding of the IACS
Regulations, requirements, and governance of relevance (Government, Industry,
Company)
Architecture diagrams
Configuration Files
Known vulnerabilities
Define roles and responsibilities
Establish training requirements
System Architecture Diagrams - ANSWER-Depiction of system components, their
connectivity, and physical locations.
Physical System Architecture Diagram - ANSWER-A diagram that provides a visual
representation of the physical components within a system and their interconnections. It
focuses on hardware elements such as servers, network devices, control systems, and
terminals, showing how these components are arranged and connected.
Functional System Architecture Diagram - ANSWER-A diagram that describes the
functions of a system and their relationships without focusing on physical details. It
presents a logical view of the system, emphasizing software elements, data flows, and
interactions between different functions or modules within the system.
(True/False) IACS functionality should be graphically represented on at least one IACS
Architecture drawing - ANSWER-True
, ISA-95 Functional Layer Level 0 - ANSWER-The physical process — This level defines
the physical processes showing data flowing from sensors and actuators into the control
level.
ISA-95 Functional Layer Level 1 - ANSWER-Intelligent devices — Devices in this level
sense and manipule the physical processes. Process, sensors, analyzers, actuators
and related instrumentation. This layer shows how PLCs receive field device data,
process it, and then send commands back to the field devices.
ISA-95 Functional Layer Level 2 - ANSWER-Control systems — Supervising,
monitoring and controlling the physical processes. Real-time controls and software;
DCS, human-machine interface (HMI); supervisory and data acquisition (SCADA)
software. This level represents how the control systems manage PLCs, how operator
commands are processed, and how alarm conditions are handled.
ISA-95 Functional Layer Level 3 - ANSWER-Manufacturing operations systems —
Managing production workflow to produce the desired products. Batch management;
manufacturing execution/operations management systems (MES/MOMS); laboratory,
maintenance and plant performance management systems; data historians and related
middleware. Time frame: shifts, hours, minutes, seconds.
ISA-95 Functional Layer Level 4 - ANSWER-Business logistics systems — Managing
the business-related activities of the manufacturing operation. ERP is the primary
system; establishes the basic plant production schedule, material use, shipping and
inventory levels. Time frame: months, weeks, days, shifts. This level shows how
enterprise systems deal with production planning and overall business logistics, and
how this information is sent down to lower levels.
(True/False) ISA-95 functional layers are the same thing as the Purdue Enterprise
Reference Architecture (PERA) - ANSWER-False
(True/False) ISA-95 functional layers speak to functionality - NOT systems or network
layers. - ANSWER-True
ISA-95 Control Domain - ANSWER-Level 3, 2, 1, 0
ISA-95 Enterprise Domain - ANSWER-Level 4
What ISA-95 levels are critical to safety, reliability, efficiency, and quality - ANSWER-
Levels 3, 2, 1, 0 (The Control Domain)
At a minimum, Network Diagrams should include... - ANSWER-Physical or Logical
connections
Individual network devices represented symbollically
Switch port assignments
