Event abstraction is a technique used to simplify complex event logs and process models by aggregating or generalizing events based on certain criteria. Here's how you can effectively utilize event abstraction to improve the readability and manageability of complex process models:

1. **Identify abstraction criteria**: Determine the criteria on which you want to abstract events. This could be based on:
   - Event type (activity name)
   - Resource (performer of the activity)
   - Timestamp (time interval)
   - Data values (attributes of events)
   - Case (process instance) characteristics

2. **Group similar events**: Group together events that match the abstraction criteria. For example, if you choose 'event type' as the criterion, group all events with the same activity name.

3. **Aggregate event data**: Once you have grouped similar events, aggregate their data to create a single, abstract event. The aggregated data could include:
   - Frequency: The number of times the event occurred in the group.
   - Duration: The time taken for the group of events to complete.
   - Data range: The minimum, maximum, and average values of relevant attributes.
   - Variants: The different paths or variants followed within the group of events.

4. **Create abstract activities**: Replace the group of similar events with a single, abstract activity in your process model. This activity should represent the essence of the original events and provide a clear, concise label.

5. **Use clear labels and annotations**: When creating abstract activities, use descriptive labels that convey the purpose or outcome of the original events. Additionally, annotate the abstract activity with relevant information, such as the number of variants, average duration, or data range, to provide context.

6. **Visualize abstract activities**: Use different visual cues, such as color, shape, or font, to distinguish abstract activities from concrete activities in your process model. This helps improve readability and understanding.

7. **Iterate and refine**: Event abstraction is an iterative process. After creating abstract activities, review your process model and refine the abstraction criteria or aggregated data as needed to better represent the underlying process.

8. **Maintain traceability**: While abstracting events, ensure that you maintain traceability links between the abstract activities and the original events. This allows you to drill down into the details of the abstract activity if needed.

By effectively utilizing event abstraction, you can create more readable and manageable process models from complex event logs. This helps in better understanding, analyzing, and improving business processes.