On the Potential of Multi-Task Learning in Predictive Process Monitoring
Organizations: University of Mannheim
Abstract
Predictive Process Monitoring (PPM) forecasts how ongoing organizational processes unfold, enabling information systems to move beyond execution support toward proactive analysis and monitoring. Although deep learning has improved prediction accuracy in PPM, most approaches follow a single-task learning (STL) setup, training a separate model per task. This increases maintenance effort and overlooks potential synergies. Multi-task learning (MTL), which jointly learns multiple prediction targets in one model, offers a promising alternative, yet its effectiveness in PPM remains underexplored. It remains unclear whether and under which settings MTL improves upon STL, which prediction tasks benefit most from joint learning, which task combinations are particularly synergistic, and if and how tasks should be balanced. To fill this gap, we present the first comprehensive empirical study of MTL for PPM, evaluating a variety of task combinations, neural architectures, and optimization methods. Overall, our results position MTL as a strong paradigm for PPM: we see substantial improvements in next-activity prediction and inherent mitigation of class imbalance using MTL, while task balancing is especially critical under low-capacity models.
Figures & tables
| Tasks | Arch. | STL | Com. | MTO | Analysis | |
|---|---|---|---|---|---|---|
| Tax et al. (2017) | 2 | L | ✓ | EW | ||
| Gherissi et al. (2022) | 3 | L | EW | |||
| Camargo et al. (2019) | 3 | L | ✓ | EW | ||
| Taymouri et al. (2020) | 2 | L | EW | |||
| Hennig and Schmidt (2025) | 3 | T | EW | |||
| Wang et al. (2024) | 3 | T | static |
| Event log | Cases | Events | ACT | RES | Variants | ALT |
|---|---|---|---|---|---|---|
| P2P | 608 | 9119 | 21 | 27 | 70 | 21.5 |
| Production | 225 | 4503 | 24 | 41 | 217 | 20.6 |
| Helpdesk | 4580 | 21348 | 14 | 22 | 226 | 40.9 |
| Sepsis | 1050 | 15214 | 16 | 26 | 846 | 28.5 |
| BPIC20DD | 10500 | 56437 | 17 | 7 | 99 | 11.5 |
| BPIC20ID | 6449 | 72151 | 34 | 8 | 753 | 86.5 |
| Model | NAP | NTP | RTP |
|---|---|---|---|
| LSTM | 0.004 | 0.250 | 0.055 |
| CNN | 0.004 | 0.570 | 0.734 |
| Transformer | 0.008 | 0.008 | 0.742 |
| Log | MTO | NAP | NTP | RTP | ||
|---|---|---|---|---|---|---|
| ACC | macro-F1 | MAE | MAE | |||
| P2P | STL | 0.73 (0.01) | 0.65 (0.01) | 1.07 (0.08) | 4.47 (0.11) | / |
| EW | 0.86 (0.00) | 0.78 (0.01) | 1.08 (0.07) | 4.73 (0.15) | -4.19 | |
| GradDrop | 0.87 (0.01) | 0.78 (0.01) | 1.03 (0.02) | 4.41 (0.09) | -8.05 | |
| IMTL | 0.85 (0.01) | 0.78 (0.01) | 1.07 (0.08) | 5.13 (0.52) | -1.09 | |
| Production | STL | 0.44 (0.01) | 0.21 (0.01) | 0.99 (0.16) | 4.72 (0.29) | / |
| Finding | Recommendation |
|---|---|
| MTL mainly improves NAP, only minimal impact on temporal tasks. | Use MTL particularly when activity prediction is central. |
| MTL improves performance on infrequent activities. | Consider MTL when rare but relevant activities matter. |
| Equal weighting is often competitive. | Start with simple EW before using more complex MTO methods. |
| Task balancing matters under limited model capacity. | Use adaptive weighting when models are small or data is complex. |
| Task-wise effects can differ. | Monitor each task separately rather than relying only on aggregate scores. |