Add box
Event
Object
Agent
Event–Agent
Event–Object
Add barrier
Barrier
Add WHY box
Immediate Cause
Precondition
Underlying Cause
How to
Click a box type to drop it on the canvas — including Immediate Cause, Precondition, and Underlying Cause, which you can also place manually and connect by hand instead of using the +IC/+PC/+UC buttons.
Select a connector first, then click Barrier in the sidebar, to insert it inline on that connector — same result as the +B button.
Already dropped a standalone Barrier? Drag it so its icon sits on top of an existing connector and let go — it splices into that line automatically.
Drag from the small dot on a box edge to another box to connect them.
Double-click text to edit it.
Click the red E on an Agent or Object to turn it into EA/EO and auto-add a linked Agent + Object.
Click the note icon (bottom-left) on a box to attach a sticky note to it.
Click the ↻ icon (bottom-right) on an Event, Event-Agent, or Event-Object box to cycle its type.
Click the ↻ icon (bottom-right) on a Barrier box to cycle Effective → Failed → Missing → Inadequate.
Click a connector to select it, then drag the end dots to reattach it, or drag the middle dot to reroute it.
Click the +B icon on a selected connector to insert a Failed Barrier directly on that line.
Effective barriers get no WHY button — nothing to explain. Failed/Inadequate barriers get one grey +IC icon to add a single Immediate Cause, stemming straight out of the icon on a diagonal line. Missing barriers get one yellow +UC icon instead, connecting straight to an Underlying Cause — no Immediate Cause or Precondition, since a barrier that was never there has no failure-in-the-moment to explain.
Click the blue +PC icon on an Immediate Cause to add a Precondition. Click the yellow +UC icon on a Precondition to add an Underlying Cause. Add as many as needed — one Immediate Cause can have several Preconditions, and one Precondition can have several Underlying Causes.
Click the BRF badge (top-left) on an Underlying Cause box to set its Basic Risk Factor category.
Click the yellow sticky-note icon (bottom-left, beside the note icon) on a Barrier or Underlying Cause box to add a Recommendation — a separate field from the general note, meant for the corrective action tied to that box. Use the Filter button to hide Recommendation or BRF badges independently of box visibility.
Shift-click to select multiple boxes, then drag any of them to move the group. Shift+drag any single box (without clicking first) to drag it plus its whole hierarchy of children — Event/Object/Agent → Barrier → Immediate Cause → Precondition → Underlying Cause.
Dragging an EA or EO box moves everything connected to its left with it. Hold Ctrl/Cmd while dragging any box to force this for that drag.
Click a box or line then press Delete or Backspace to remove it.
Use the Filter button (top bar) to show only WHAT (Trios), HOW (+ Barriers), WHY (+ Immediate Cause/Precondition/Underlying Cause), or a custom mix — this only changes what's shown, your data is untouched.
Use the canvas tabs (below the top bar) to work on more than one diagram in this file — click the ✎ icon or double-click a tab's name to rename it, + Canvas for a new blank one, Duplicate to copy the current one.
Select a connector first, then click Barrier in the sidebar, to insert it inline on that connector — same result as the +B button.
Already dropped a standalone Barrier? Drag it so its icon sits on top of an existing connector and let go — it splices into that line automatically.
Drag from the small dot on a box edge to another box to connect them.
Double-click text to edit it.
Click the red E on an Agent or Object to turn it into EA/EO and auto-add a linked Agent + Object.
Click the note icon (bottom-left) on a box to attach a sticky note to it.
Click the ↻ icon (bottom-right) on an Event, Event-Agent, or Event-Object box to cycle its type.
Click the ↻ icon (bottom-right) on a Barrier box to cycle Effective → Failed → Missing → Inadequate.
Click a connector to select it, then drag the end dots to reattach it, or drag the middle dot to reroute it.
Click the +B icon on a selected connector to insert a Failed Barrier directly on that line.
Effective barriers get no WHY button — nothing to explain. Failed/Inadequate barriers get one grey +IC icon to add a single Immediate Cause, stemming straight out of the icon on a diagonal line. Missing barriers get one yellow +UC icon instead, connecting straight to an Underlying Cause — no Immediate Cause or Precondition, since a barrier that was never there has no failure-in-the-moment to explain.
Click the blue +PC icon on an Immediate Cause to add a Precondition. Click the yellow +UC icon on a Precondition to add an Underlying Cause. Add as many as needed — one Immediate Cause can have several Preconditions, and one Precondition can have several Underlying Causes.
Click the BRF badge (top-left) on an Underlying Cause box to set its Basic Risk Factor category.
Click the yellow sticky-note icon (bottom-left, beside the note icon) on a Barrier or Underlying Cause box to add a Recommendation — a separate field from the general note, meant for the corrective action tied to that box. Use the Filter button to hide Recommendation or BRF badges independently of box visibility.
Shift-click to select multiple boxes, then drag any of them to move the group. Shift+drag any single box (without clicking first) to drag it plus its whole hierarchy of children — Event/Object/Agent → Barrier → Immediate Cause → Precondition → Underlying Cause.
Dragging an EA or EO box moves everything connected to its left with it. Hold Ctrl/Cmd while dragging any box to force this for that drag.
Click a box or line then press Delete or Backspace to remove it.
Use the Filter button (top bar) to show only WHAT (Trios), HOW (+ Barriers), WHY (+ Immediate Cause/Precondition/Underlying Cause), or a custom mix — this only changes what's shown, your data is untouched.
Use the canvas tabs (below the top bar) to work on more than one diagram in this file — click the ✎ icon or double-click a tab's name to rename it, + Canvas for a new blank one, Duplicate to copy the current one.
Click a box type on the left to start building your diagram.