1. An authoring tool, comprising: a flowchart module to create or modify a diagnostic test sequence, the flowchart module including a first display image with a plurality of selectable fields to facilitate creating or modifying the diagnostic test sequence; a panel editor module to create or modify a display panel that displays an instruction associated with the diagnostic test sequence during diagnostic testing, the panel editor module including a second display image with a plurality of selectable fields to facilitate creating or modifying the display panel; and an expression editor module to create or modify a logical expression associated with the diagnostic test sequence, the expression editor module including a third display image with a plurality of selectable fields to facilitate creating or modifying the logical expression; wherein the flowchart module incorporates the display panel and the logical expression into the diagnostic test sequence.