The workflow engine only creates a human task once its predecessors are done, so a skipped task mostly comes from outside (a task reported done from the field, a task added by hand).
Conformance checking
Process mining applied live (token replay, in the spirit of van der Aalst): what the actors did in their To-Do Lists is replayed on the process the deduction found. Every deviation (a task started too early, refused, failed or unknown to the process) adds its weight to the Failing category: the process is no longer followed as deduced.
implemented byConformanceCheckingStrategy · ProcessGraph · gind-npm-strategy-supervision-conformance-checking
01 · Deviations
Five kinds, five weights
| Deviation | Detected when | Default weight |
|---|---|---|
| Skipped | A task was started while a task it follows is not done; or, through a conditional gateway, while none of the tasks it may follow is done. | 1 |
| Disorder | A task was started before a task it follows was done, which ended later. | 0.5 |
| Rejected | An actor refused the task (Acceptance = REJECT). | 1 |
| Error | The task ended in error and no exception flow of the process handles it. | 1 |
| Unexpected | A task of the To-Do Lists of the process is not in the process of the solution (added on the way, a recovery). | 0.5 |
Failing = Σ weights of the deviations / threshold threshold 1: one skipped, rejected or failed task fires the alert, two disorders or two unexpected tasks too
02 · The process graph
Which tasks follow which
Predecessors through the gateways — going back along the nominal flows from a task, through gateways and events, gives the tasks it follows. Behind a join of a conditional gateway (exclusive, inclusive, complex) they are only needed one of them: the task is skipped only when none of them is done.
Branches not taken — once the process reached a task in one branch of an exclusive gateway, the tasks of the other branches will never run: they are never “skipped”.
Passed by the engine — a task which never appears in a To-Do List (a move, an automatic task) was passed by the workflow engine itself: it is never a deviation, it counts as done.
Contingent tasks — the tasks reached through an exception or event flow are contingent: they run only when something goes wrong, and their absence is normal.
03 · Parameters
In the supervision box
| Parameter | Default |
|---|---|
| Skipped task | 1 |
| Disordered tasks | 0.5 |
| Rejected task | 1 |
| Task in error | 1 |
| Unexpected task | 0.5 |
| Failing threshold | 1 |
A weight of 0 ignores the deviation.
04 · Example
IMT Albi Crisis: an actor refuses a task
After “Confirm gas leak” (answer “Yes and repairable”), the process gives “Cut off the local gas valve” to Emily Hernandez. She rejects it: Failing = 1 / 1 = 1.00 with the contribution “"Cut off the local gas valve" was rejected by its actor”, and the alert box opens on Failing, proposing to reassign the remaining tasks.
05 · Watch points
Good to know
A corrective sub-process deployed on the way creates tasks unknown to the solution: they count as unexpected, with half a weight.
gind-detection-engine-conformance-checking-strategy/…/ConformanceCheckingStrategy.javaReplay and weights of the deviations.gind-detection-engine-abstract/…/ProcessGraph.javaPredecessors through the gateways, discarded branches, contingent tasks.