ICS Cybersecurity Services

ISA/IEC-62443/ISA-99 Based Control System Cybersecurity High Level Risk Assessment

The move by most, if not all, DCS vendors towards “open systems” and the resulting incorporation of off-the-shelf technologies represented a significant shift in control system design. System integration became easier, product development by manufacturers was accelerated, and training was simplified as it leveraged common tools and concepts. While the benefits have been tremendous, at the same time, open technology has now allowed control systems to be exposed by frequent and significant security vulnerabilities, putting production, assets, and human safety at risk. Gone are the days of proprietary operating systems and communication busses, isolated systems, and inherently secure processing environments.

In today’s interconnected world, a successful cyber-attack represents a potential common mode source that can both cause the demand and prevent instrumented safeguards from performing their safety function. Understanding the integration of Cybersecurity into the Safety Lifecycle is key to the complete Process Safety Management Lifecycle. 

A Control System Cybersecurity High Level Risk Assessment (CHLRA) 

  • Intended to be a quick, high-level assessment of risk, based on process functional area.
  • Designed to assist the establishment of scope for new projects and to provide a determination of the criticality of various devices relative to cybersecurity. 
  • Provides a valuable input when establishing zone and conduit security.
  • An excellent means to document an initial definition of expected response should a device be compromised.
  • Provides documentation required by regulators, insurance companies and any other stakeholders.

The Process

The process can be broken down into three phases: 

Phase 1

  • Information collection
  • Collect inventory of devices, 
  • Organize device inventory as a function of process/utility areas
  • Document the corporate tolerable risk criteria e.g. Risk Matrix
  • Document major hazards within each process/utility area under review.

Phase 2

  • Onsite team review of device criticality for each applicable process utility area.

Phase 3

  • Analysis and documentation of the results in an assessment report.


  • Assists with the document on how short, medium and long term business interruption, e.g. hour, hours, days,months, relates to cost so as to not overestimate consequences
  • Avoids treating everything as a highest level risk consideration using valuable assets and resources.
  • Provides a foundation and direction towards developing a broader security program Short Duration – most systems can be assessed in less than a day or two - and minimally invasive to personnel, and non invasive to the PCN itself.

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