Loops, Duplicate task and Heuristic Miner.

joaogoc

Hello everyone,
I have a question about loops, duplicate tasks and Heuristic Miner. Well, if i have a loop of the same activity (for example A-A-A ...) is it considered a loop in a duplicate task?
Is the heuristic miner unable to determine duplicate tasks? These questions are because I have a log that contains some equal tasks in a row (supposed loop) and the heuristic miner in this case says that the task only happens once. So a loop can have duplicate tasks and therefore the heuristic miner cannot present correctly?

hverbeek

Hi,

The heuristics miner cannot handle/discover duplicate tasks. If it encounters multiple A events in a trace, then it will map all these events to a single A task in the model.

I do not fully understand your question. You mention that you have "a log that contains some equal tasks in a row". Do you mean you have a log with multiple A events in some traces, or a model with multiple A tasks?

Kind regards,

Eric.

joaogoc

Here is an example where "C" appears three times. I suppose we are present before a "loop". So the Heuristic Miner presents "C" only once?

hverbeek

Hi,

I do not know by heart, but it is quite possible that the heuristics miner cannot discover such short (length one) loops. If it cannot discover the loop nor duplicate tasks... On a trace like ABCGCGCDEF, it might be able to detect a (length two) loop.

Kind regards,

Eric.

hverbeek

It can also be that the loop was removed because of the thresholds that were used for the discovery. If you lower the thresholds, the loop (even the length one loop) just may be discovered.

Eric.

joaogoc

I'm testing some algorithms with different "logs" in ProM 5.2, with the default settings. I even read that heuristic miner was not able to calculate duplicate tasks (I don't know if only short). If a loop of the same task is considered a duplicate task, then from what I understand, Heuristic miner is unable to correctly present that task.

hverbeek

If you have an event log where A occurs twice in every trace, then the heuristics miner might discover a (short) loop, but it will not discover that A is a duplicate task. It just cannot result in a net where two tasks have the same name. It cannot do that.