What ’ s New at IIC : June 2021 Principle 8 : Implementing trustworthiness means implementing trustworthiness methods . Principle 9 : Maintaining change and audit records is necessary for trustworthiness . Principle 10 : A trustworthiness framework must enable timely business decisions . Principle 11 : Assurance requires a systems viewpoint with evidence of multiple factors .
Note , in particular , principle 8 . The first challenge of implementing trustworthiness in system design is that none of the trustworthiness characteristics can be implemented separately and they cannot be simply combined : The characteristics may support or block each other ; their combination results in new challenges . The solution is to take the system design away from the trustworthiness characteristics to methods that are assigned to the system characteristics . A trustworthiness method is a component , tool , technology , software application , operational procedure or management directive that is assigned to at least one trustworthiness characteristic .
Examples of trustworthiness methods are :
• Fire extinguisher : a tool and a trustworthiness safety method .
• CO 2 fire suppression system : a tool and a trustworthiness resilience method ( the purpose is to protect the system , not the environment or humans ; CO 2 is dangerous to people ).
• Windmill restart : operational procedure for airplanes during an engine flameout and a trustworthiness resilience method .
• Encryption of all social security numbers on servers : management directive and a trustworthiness privacy method .
The framework also provides ways to think about how the state of the system can be changed by applying the trustworthiness methods .
The trustworthiness framework :
• is flexible to include metrics as appropriate to the target context and audience ,
• is stateful to allow accounting for both the history of the system and the current information about its trustworthiness ,
• supports hierarchical decomposition to evaluate the effects of trustworthiness in different layers of the system and
• facilitates a simple visualization with relevant information .
The model also quantifies performance of the system in many operational areas , some of which may be unique to the system under consideration . A rating for each of these areas can be defined
- 64 - June 2021