2003 Northeast Blackout
In 2003, the United States experienced the Northeast Blackout, which had significant cascading effects, impacting various aspects of society and infrastructure. According to Practical Engineering, in the February 2022 article “What Really Happened During the 2003 Blackout,” they identified some of the key consequences of that event:
- Widespread Power Loss: The blackout affected approximately 55 million people across the Northeastern and Midwestern United States and parts of Canada. Major cities like New York, Toronto, and Detroit experienced complete power loss.
- Economic Impact: The blackout resulted in an estimated economic loss of over $10 billion due to halted business operations, lost productivity, and spoilage of perishable goods.
- Transportation Disruptions: Public transportation systems, including subways and trains, were severely disrupted. The subway system was shut down in New York City, stranding thousands of commuters.
- Water Supply Issues: Many areas experienced water supply problems as electric pumps failed. This led to a lack of water pressure and, in some cases, contamination concerns.
- Emergency Services Strain: Emergency services were overwhelmed with calls, and the lack of power affected their ability to respond efficiently. Hospitals had to rely on backup generators, and some faced challenges in maintaining critical operations.
- Communication Breakdowns: Telecommunications were disrupted, making it difficult for people to contact emergency services or stay informed about the situation.
- Social and Psychological Effects: The sudden loss of power and the uncertainty of the situation caused stress and anxiety among the affected population. There were also reports of increased crime rates in some areas during the blackout2.
Can you imagine today's cost of a cascading event if we lose data centers and internet services? When you have a poor reputation, you may lose customers completely, and in some cases, you may even be subject to civil suits for negligence.
Identifying Risks and Risk Mitigation
There are many forms of risk assessment, but whatever assessment methodology, tool, or solution you choose, ensure that it provides you with the critical information you need to make sound decisions. We strongly recommend a qualitative and quantitative risk assessment considering all human-made, accidental, and technological hazards. A checklist is great for compliance but serves little use when identifying risk-based events and their impacts on the organization's strategic mission.
One method to support a good risk assessment is fault tree analysis (FTA), sometimes known as event tree analysis. FTA identifies the possible causes of a system failure. Essentially, we identify low-level failures that can result in system failure due to a lack of redundancy.
A FTA graphically illustrates the different potential causes of a failure in a diagram. Using FTA, you can determine what factors contributed to an event (known as a failure) and the probability of it occurring. Once the major causes are identified and addressed, FTA can help teams prioritize corrective actions.
In FTA, we have “and gates” and “or Gates to demonstrate the fundamental components used to model the logical relationships between different events leading to a system failure. In Fault Tree Analysis (FTA), AND and OR gates represent different logical relationships between events that can lead to a system failure. Here's a detailed explanation of each:
All Risks Are Shared
Once you have completed your risk, threat, and vulnerability assessment, you should consider the Concept of a shared operations center in terms of cyber, physical operations, environmental health and safety, and business continuity.
AND Gate
- Definition: An AND gate indicates that all input events must occur simultaneously for the output event to happen. It represents a situation where multiple conditions need to be met for a failure to occur, such as system redundancy.
- Symbol: The symbol for an AND gate is a flat-topped shape with multiple input lines converging into it.
- Example: If a system failure occurs only when both a power supply and a backup generator fail, these two events would be connected by an AND gate. This means both failures must happen together for the system to fail.
OR Gate
- Definition: An OR gate indicates that at least one of the input events must occur for the output event to happen. It represents a situation where one of several conditions can cause a failure. Or gates represent single points of failure.
- Symbol: The symbol for an OR gate is a curved shape with multiple input lines converging into it.
- Example: If a system failure can occur due to either a power supply failure or a software malfunction, these two events would be connected by an OR gate. This means that either failure can independently cause the system to fail.
Here is an example of a Fault Tree Analysis for a Power Outage:
Top Event: Power Outage
1. Transmission Line Failure (OR Gate)
- Conductor Failure (AND Gate)
- Conductor Breakage
- Conductor Corrosion
Insulator Failure (AND Gate)
- Insulator Cracking
- Insulator Contamination
2. Substation Failure (OR Gate)
Transformer Failure (AND Gate)
- Overheating
- Insulation Breakdown
Circuit Breaker Failure (AND Gate)
- Mechanical Failure
- Electrical Fault
3. Generation Failure (OR Gate)
Generator Breakdown (AND Gate)
- Mechanical Wear
- Cooling System Failure
Fuel Supply Interruption (AND Gate)
- Fuel Shortage
- Supply Line Damage
In this example, the top event is the power outage. The intermediate events (e.g., transmission line failure, substation failure, generation failure) are connected to the top event using OR gates, indicating that any failures can cause a power outage. Each intermediate event is further broken down into essential events (e.g., conductor breakage, insulator cracking) using AND gates, indicating that multiple conditions must be met for the intermediate event to occur. An FTA diagram helps identify potential points of failure and their causes, allowing for better risk management and mitigation strategies.
