Safety Evaluator

Definition

Safety Evaluator

the role that is played when a person independently evaluates the safety case to determine if the system will meet its safety-related requirements

Classification

As illustrated in the preceding figure, Safety Evaluator is part of the following inheritance hierarchy:

• Type: Concrete
• Superclass: Engineer
• Subclasses:
  • None

Responsibilities

The typical role-specific responsibilities of a Safety Evaluator are to:

• Plan the safety evaluation effort.
• Provide a thorough, independent, and objective review of the development organization’s performance of the safety engineering tasks. Safety evaluators will:
  • Evaluate the development organization’s process for performing safety engineering.
  • Determine the validity of requests for waivers or deviations from the safety engineering process.
  • Evaluate all safety-related documentation.
  • Evaluate the validity of all safety analyses performed for the system.
  • Determine if the levels of trust (LOT) have been correctly assigned to safety-related requirements.
  • Determine if the safety integrity levels (SILs) have been correctly assigned to system components.
  • Evaluate the selection of the safety tools.
  • Determine if the safety tools are being effectively used.
  • Evaluate any formal requirements specifications and formal proof of correctness of designs for consistency, structure, and appropriateness.
  • Evaluate the adequacy of the design and implementation of system components with regard to safety.
  • Evaluate the adequacy of the safety testing of system components, their integration, and the resulting system.
• Evaluate the technical validity of the safety case (at intermediate milestones and upon completion). Safety evaluators will:
  • Evaluate the adequacy and validity of the safety goals.
  • Evaluate the adequacy and validity of the safety arguments.
  • Evaluate the adequacy and validity of the safety evidence.
• Report the results of the safety evaluations.

Safety Evaluator typically inherits the general role responsibilities from the role method component.

Expertise

To fulfill these responsibilities, safety evaluators typically should have the following expertise, training, and knowledge:

• Expert knowledge of and experience with safety engineering tasks, techniques, and tools.
• Expert knowledge of safety architectural mechanisms and components.
• Solid knowledge of safety requirements.
• Basic knowledge of the customer’s business and application domain(s).
• A bachelor’s degree in software engineering, computer science, or the equivalent.
• One of the following safety certifications:
  • TBD

Tasks

Safety evaluators typically perform the following role-specific tasks in an iterative, incremental, parallel, and time-boxed manner:

• Safety Engineering:
  • Safety Compliance Assessment

Safety evaluators typically inherit common role tasks from the role method component.

Teams

Safety evaluators typically perform these tasks as members of the following teams:

• Safety Team

Work Products

As members of these teams, safety evaluators typically produce all or part of the following work products:

• Safety Work Products:
  • Safety Evaluation Plan
  • Safety Compliance Assessment Report

Guidelines

• The safety evaluator should be managerially and commercially independent of the customer organization, development organization, and the safety auditor.
• If there is no safety evaluator, then the role may be played by a safety engineer with sufficient independence, both organizationally and financially, to fulfill the responsibilities without any possible conflict of interest.
• The safety evaluator must not have taken part in the development of the system.
• The safety evaluator must be given free access to all system documentation that is relevant to the evaluation of system safety.
• The safety evaluator must have free access to the development site in order to determine first hand how safety-related development and analysis activities are being carried out.
• This role typically inherits the common team guidelines from the roles process component.