Operator Function Model

Operator Function Model (OFM) is a systems engineering technique used to analyze and represent human tasks within complex systems, particularly in the context of human-machine interaction. OFM is used to describe and understand the roles, responsibilities, and actions of operators or users within a system. It helps in designing more effective and efficient systems by identifying potential issues and areas for improvement in human-machine interaction.

Purpose and Role: The purpose of the Operator Function Model is to analyze the human element within a system and understand how operators interact with the technology, tools, and processes. The role of OFM is to provide a structured framework for representing the tasks, information flow, and decision-making processes involved in the operation of a system. This helps designers and engineers create more user-centered and effective systems, ensuring seamless integration between human operators and technology.

Components: The key components of an Operator Function Model include:

  1. Functions: The specific tasks or actions performed by the operator within the system.
  2. Inputs: The information, data, or resources required by the operator to perform their functions.
  3. Outputs: The results, products, or information produced by the operator after performing their functions.
  4. Decision-making: The cognitive processes and choices made by the operator during task execution.
  5. Information flow: The flow of data and information between the operator and the system.
  6. Feedback loops: The feedback mechanisms that allow the operator to monitor and adjust their actions based on system performance or environmental changes.

Importance: The Operator Function Model is important because it helps engineers and designers understand the human element in complex systems and identify potential issues and areas for improvement. By modeling the tasks and interactions between operators and the system, OFM provides insights into how the system can be designed to be more efficient, user-friendly, and effective.


  1. Improved system design by focusing on human-machine interaction.
  2. Identification of potential issues and areas for improvement.
  3. Streamlined and efficient task execution.
  4. Enhanced operator performance and system effectiveness.
  5. Reduced potential for human error.

Pros and Cons: Pros:

  1. Focuses on the human element within a system.
  2. Provides a structured framework for analyzing and representing human tasks.
  3. Helps design more user-centered systems.
  4. Can lead to improved system performance and reduced errors.


  1. May require significant time and effort to develop detailed OFMs.
  2. The effectiveness of the model is dependent on the accuracy and completeness of the information used.

Examples to illustrate key concepts:

  1. In an air traffic control system, an OFM can be used to analyze the tasks and responsibilities of air traffic controllers, such as monitoring aircraft positions, coordinating takeoffs and landings, and communicating with pilots. By modeling the interactions between controllers and the various tools and systems they use, designers can identify opportunities for improvement in the user interface, decision support tools, and overall system performance.
  2. In a manufacturing environment, an OFM can be developed to understand the tasks performed by operators at different stages of the production process. This can help identify bottlenecks, inefficiencies, and potential sources of error, leading to more efficient and effective production systems.

In conclusion, the Operator Function Model is a valuable tool for understanding and analyzing the human element within complex systems. By focusing on human-machine interaction, OFM can help engineers and designers create more effective and efficient systems that seamlessly integrate human operators with technology.

See Also