Controllers and Controlled Processes are HCS modelling elements. They are visualized as rectangles with a label representing the name of the controller or controlled process respectively. The icon in the upper left corner indicates the type of element. Throughout the modeling and diagramming process, there are multiple ways to rename a controller set on the canvas: With respect to the deletion of controllers the STPA Module differentiates between: Reminder: the “Del” key deletes the controller from the diagram only. A controller may be converted into a controlled process and vice versa via the Properties panel. Note that converting a controller into a controlled process is disabled if the controller issues control actions, because this goes against the STPA HCS modelling rules, where a controlled process can’t issue control actions During the modeling and diagramming process, copying and pasting elements and connectors can save a lot of time. The Annotation Layer is very useful when diagramming and can be used within the canvas through various elements. Annotation Elements are aesthetic elements that can be used on the Diagrams for more descriptive purposes. They hold no data on their own and do not affect the Model in any way. Annotations can be enabled and disabled with a single click by using the button on the Toolbar on top of the canvas. 10.2.2.1.Diagram Elements
Diagram Elements
Objects – Controllers and Controlled Processes
Icon shown for Controllers
Icon shown for Controlled Process
How To: Create Controller (analogously for Controlled Processes)
How To: Rename Controller (analogously for Controlled Processes)
How To: Delete a Controller (analogously for Controlled Processes)
How To: Convert Controller to Controlled Process and vice versa
How To: Cut Copy Paste Controllers (analogously for Controlled Processes)
Actions – Control Actions and Feedback
How to: Create Control Actions and Feedback
Annotation Layer