Object-centric Process Mining Model

Note: This page describes functionality that hasn't fully been released.

QPR ProcessAnalyzer supports object-centric process mining (OCPM) based on the OCEL 2.0 standard (https://www.ocel-standard.org). To use OCPM, you need to create an OCPM model. The OCPM model can be analyzed in the OCPM flowchart and regular charts through converting the OCPM eventlog into case-centric eventlogs using OCPM perspectives.

Create object-centric model

Create a new object-centric model as follows:

1. In the Workspace, open the project where to create the model.
2. Select NEW" in the top right menu and select model.
3. Define a name for the new model.
4. Set Model type as Object-centric.
5. Click Create.

Configure object-centric model datatables

Datatables for the object-centric model need to exist in the same project as the model. Datatables can be set for the model as follows:

1. In the Workspace, select the object-centric model and click Properties.
2. In the model properties dialog, open the Datasource tab.
3. Add a following kind of json configuration to the textbox:

{
  "Objects": "OCPM: objects",
  "Events": "OCPM: events",
  "ObjectToObject": "OCPM: object-object",
  "EventToObject": "OCPM: event-object",
  "ObjectTypes": {
    "Invoice": "OCPM object: Invoice",
    "Payment": "OCPM object: Payment",
    "Purchase Order": "OCPM object: Purchase Order"
  },
  "EventTypes": { 
    "Approve Purchase Requisition": "OCPM event: Approve Purchase Requisition",
    "Change PO Quantity": "OCPM event: Change PO Quantity",
    "Create Purchase Order": "OCPM event: Create Purchase Order",
    "Insert Invoice": "OCPM event: Insert Invoice",
    "Insert Payment": "OCPM event: Insert Payment"
  }
}

The json configuration needs to have following properties:

• Objects: Objects datatable name.
• Events: Events datatable name.
• ObjectToObject: Object-to-object relation datatable name.
• EventToObject: Event-to-object relation datatable name.
• ObjectTypes: Key-value-pairs of object type datatable names. Note that object names need to match with object names in the objects datatable.
• EventTypes: Key-value-pairs of event type datatable names. Note that event names need to match with event names in the events datatable.

Import from OCEL 2.0 JSON file

Object-centric model can be import from an OCEL 2.0 JSON file as follows:

1. In the Workspace, open the project where to import the model.
2. Select NEW in top right menu and select Import Model.
3. Select the OCEL 2.0 JSON file from the disk and click Open.

An object-centric model and a list of datatables is created.

OCPM model structure

OCPM model uses datatables described in the table below. Datatables can be named freely because the model configuration selects the datatable for each type of data. The datatables need to use the column names specified in the table below because those are the column names assumed by the OCPM calculation.

Datatable	Content	Columns
Objects	Objects in the model (one row per object).	OcelObjectId: Unique id for the object (among all objects in the model). OcelObjectType: Object type name (such as Order, Invoice, Delivery).
Events	Events in the model (one row per event).	OcelEventId: Unique id for the event (among all events in the model). OcelEventType: Event type name (such as Order created, Invoice sent). OcelEventTime: Event timestamp.
Object-object relations	Relations between objects (one row per relation).	OcelObjectObjectSourceId: Source object id of the relation. OcelObjectObjectTargetId: Target object id of the relation. OcelObjectObjectQualifier: Describes the type of the relation (not used currently).
Event-object relations	Relations between events and objects (one row per relation).	OcelEventObjectSourceId: Object id of the relation. OcelEventObjectTargetId: Event id of the relation. OcelEventObjectQualifier: Describes the type of the relation (not used currently).
Object attributes (several tables)	Object attribute values, each object type in a separate table (one row per object).	OcelObjectTypeObjectId: Object id. OcelObjectTypeTime: Timestamp where the attribute value is valid from (not used currently). OcelObjectTypeChangedField: Changed attribute name (not used currently). <Object attributes>: Columns for each of the object attribute values (column name is the attribute name).
Event attributes (several tables)	Event attribute values, each event type in a separate table (one row per event).	OcelEventTypeEventId: Event id. <Event attributes>: Columns for each of the event attribute values (column name is the attribute name).

OCPM perspectives

Perspectives convert an OCPM model into the traditional case-centric model, allowing to analyze OCPM models in charts in dashboards. A single perspective is not able describe the OCPM model entirely, but just from a certain limited "perspective". By using several perspectives, it's possible to get a more complete picture of the OCPM model. The perspective starts from a certain object type and traverses the object-object relations as many steps as desired.

To define a perspective, the following settings are defined:

• Base Object type: The object type that all events are projected to.
• Object Relation Steps: Specifies how many object-object relations will be traversed in order to find events connected to the base objects. Value zero means that only those events are returned that are directly connected to the base object.
• Show Event Types: List of event type names whose attributes are to be included into the perspective. If not defined, all the event types will be included, but their event attributes are not included.

The resulting perspective eventlog will have the following columns:

• OcelObjectId (mapped to case id)
• OcelEventType (mapped to event type)
• OcelEventTime (mapped to timestamp)
• OcelEventId
• All object attributes in the perspective's select object type.
• All event attributes in all the perspective's select event types.

Differences to OCEL 2.0 standard

The OCPM models in QPR ProcessAnalyzer are mainly following the OCEL 2.0 standard, but there are the following exceptions:

• Changing of object attributes values over time is not supported.
• ocel_time field of each event type table is moved to events table as every event anyways has a timestemp.
• *_map_type are not needed as the model settings are used for the same purpose.
• Object type tables: If OcelObjectTypeChangedField is not null, all the other field values are copied from the previous entry having the same OcelObjectTypeObjectId, except:
  • OcelObjectTypeChangedField, which has the name(s) of the changed field(s) as comma separated string.
  • The actual changed field, which has the new value.
  • OcelObjectTypeTime, which has the timestamp when the value changed.