## 3.7 DIAAT Phase 5: Treat Risk 

T 

## 3.7.1 Overview 

In this phase, identify appropriate means to mitigate or manage the safety risk. Treating risk involves: 

• Identifying appropriate safety requirements, 

TREAT RISK 

 Choose risk management strategies  Develop safety performance targets  Develop monitoring plan 

• Defining safety performance targets or a sound alternate method to verify the predicted residual risk for each hazard, and 

• Developing a monitoring plan that prescribes tasks and review cycles for comparing the current risk to the predicted residual risk. 

## 3.7.2 Risk Management Strategies 

To address safety risk, identify and evaluate means that either manage the risk or reduce it to an acceptable level. The four risk management strategies are risk control, risk avoidance, risk transfer, and risk assumption. Assess how the proposed risk management strategy affects the overall risk. Consider using a combination of actions to best manage or reduce the risk to an acceptable level. When determining the appropriate strategy, consider how the safety performance target (see Section 4.1) will be used to evaluate the safety performance of the chosen course of action. 

## 3.7.2.1 Risk Control 

A risk control strategy  involves the development of safety requirements , defined as planned or proposed means to reduce a hazard’s causes or effects. Examples include policies or procedures, redundant systems and/or components, and alternate sources of production. Refer to Section 3.7.3 for information on developing safety requirements. 

An explanation of how a safety requirement reduced the hazard’s risk level—ultimately supported with objective evidence through testing, monitoring, or another method—must be provided for each safety requirement. All safety requirements that are implemented and are determined to have successfully addressed the hazard or safety issue become part of the operating National Airspace System (NAS). At that time, they will be considered “controls” that form the basis for future safety hazard and risk analysis efforts. Refer to Section 3.5.2 for information on controls. 

## 3.7.2.2 Risk Avoidance 

The risk avoidance strategy  averts the potential occurrence and/or consequence of a hazard by either selecting a different approach or not implementing a specific proposal. This technique may be pursued when multiple alternatives or options are available, such as determining where to construct an air traffic control tower. In some cases, a decision may be made to limit the NAS change to certain conditions or system states, thereby avoiding the risk associated with other conditions. An example of this is allowing simultaneous operations on one runway that is over-flown by three other runway flight paths. It may be discovered that the risk associated with the simultaneous operation can be mitigated to an acceptable level for two of the runways but 

