---
title: "Complex Symbolic Sequence Encodings for Predictive Monitoring of Business Processes"
type: source
tags: [ppm, outcome-prediction, encoding, data-aware, foundational]
authors: [Leontjeva Anna; Conforti Raffaele; Di Francescomarino Chiara; Dumas Marlon; Maggi Fabrizio Maria]
year: 2015
venue: "BPM 2015, LNCS 9253, Springer"
kind: paper
raw_path: "raw/Predictive process monitoring/Complex symbolic sequence encodings for predictive monitoring of business processes BPM2014.pdf"
created: 2026-04-13
updated: 2026-04-13
key_claims:
  - Traces should be treated as complex symbolic sequences — sequences of events each carrying a data payload — not just sequences of event labels.
  - Several encoding schemes (boolean, frequency, index-based, HMM) are systematically compared for outcome-prediction accuracy.
  - Accounting for the data payload materially improves predictive accuracy on real-life logs.
---

# Leontjeva et al. 2015 — Complex Symbolic Sequence Encodings

Foundational paper on [[concepts/trace-encoding|trace encodings]] for [[concepts/outcome-prediction|outcome prediction]]. Systematically compares encoding schemes on real logs — establishes the taxonomy of encodings that subsequent PPM surveys adopt.

## Contribution
- Frames traces as **complex symbolic sequences** — preserving both activity labels and per-event data payload.
- Compares encodings:
  - **Boolean** (activity occurrence)
  - **Frequency** (activity counts)
  - **Simple index-based** (first / last / sliding-window)
  - **Complex index-based** (one attribute block per position)
  - **HMM-based**
- Outcome = binary classification (positive vs negative business outcome).

## Significance
Sets the **encoding taxonomy** later cited by Teinemaa et al.'s outcome-PPM benchmark ([[sources/2016-teinemaa-outcome-ppm-review]]) and the Verenich survey ([[sources/2019-verenich-survey-ppm]]). Establishes that data-aware encodings beat control-flow-only encodings — a claim echoed by all subsequent neural PPM work.

## Connections
**Concepts:** [[concepts/trace-encoding]] · [[concepts/outcome-prediction]] · [[concepts/predictive-process-monitoring]]
**Authors:** [[entities/chiara-di-francescomarino]] · [[entities/marlon-dumas]] · [[entities/fabrizio-maggi]]