The field of process mining offers a range of techniques for evidence-based improvement of business processes. The quality of the process data used, as stored in so-called event logs, is paramount to the reliability and usefulness of the process mining outcomes. Due to the increased uptake, at scale and for more complex types of applications, the field of process mining has evolved and event logs now need to be object-centric rather than event-centric. To understand and manage the quality problems that can occur in object-centric event logs a systematic approach is required that is different from past investigations into event-centric logs. To this end, we adopt a pattern-based approach, a tried and tested method to characterise problems that are otherwise hard to capture. A new collection of patterns is presented for object-centric logs, where each pattern captures the nature of the problem, how its manifestation can be detected, and how the problem can be remedied. The pattern collection is validated through a multi-prong approach, i.e., evidence-based, literature-based, empirical, and user-based (with the process mining community). The results show that these patterns are perceived as important to identify and that they do occur in practical settings.

Detecting and repairing anomalies in business process event logs is essential for maintaining process integrity. Building on the observation that real-world anomalies often exhibit specific patterns and extending our earlier semi-supervised, rule-based approach to detect and repair common basic patterns, this paper presents an anomaly detection and repair framework powered by reinforcement learning. The proposed approach automatically learns an intelligent policy to identify and correct typical basic anomaly patterns, moving beyond the limitations of heuristic, rule-based methods. Furthermore, thanks to the flexibility provided by reinforcement learning, the approach can handle more complex patterns formed by combinations of the basic ones. Extensive evaluation using both synthetic and realworld logs demonstrates that the proposed method outperforms traditional trace alignment, edit distance-based techniques, and unsupervised deep learning in the accuracy of anomalous trace repair. It also shows consistent performance across various anomaly types and offers a pattern categorization capability that baseline methods lack.

In the context of process mining, alignments are increasingly being adopted for conformance checking, due to their ability in providing sophisticated diagnostics on the nature and extent of deviations between observed traces and a reference process model. On the downside, deriving alignments is challenging from the computational point of view, even more so when dealing with multiple perspectives in the process, such as, in particular, data. In fact, every observed trace must in principle be compared with infinitely many model traces. In this work, we tackle this computational bottleneck by borrowing the classical idea of encoding from machine learning. Instead of computing alignments directly and exactly, we do so in an approximate way after applying a lossy trace encoding that maps each trace into a corresponding compact, vectorial representation that retains only certain information of the original trace. We study trace encoding-based approximate alignments for processes equipped with event data attributes, from three different angles. First, we indeed show that computing approximate alignments in this way is much more efficient than in the exact setting. Second, we evaluate how accurate such approximate alignments are, considering different encoding strategies that focus on different features of the trace. Our findings suggest that sufficiently rich encodings actually yield good accuracy. Third, we consider the impact of frequency and density of model variants, comparing the effectiveness of using standard approximate multi-perspective alignments as opposed to a variant that incorporates probabilities. As a by-product of this analysis, we also obtain insights on how these two approaches perform in the presence of noise. • Approximate multi-perspective alignments based on trace encodings. • Formal framework to compute approximate alignments against Data Petri nets. • Extension dealing with trace probabilities. • Experimental evaluation witnessing efficiency and accuracy, also in the presence of noise.

Plan Recognition is the task of identifying the goals and plans of an agent by observing its behavior within the environment. The problem has been extensively studied in the context of planning, in particular bringing forward stochastic techniques dealing with probability distributions over the possible agent goals, under the assumption that observations are reliable. More recently, a connection between this problem and process mining techniques has been established, paving the way towards the application of alignment-based conformance checking techniques from process mining to tackle plan recognition problems in a setting where observations may be faulty. In this work, we reconcile these two lines of research in a unified framework that deals at once with uncertainty over the goals and the faithfulness of observations. Instead of using ad-hoc techniques to solve this problem, we cast it as a probabilistic trace alignment problem, trading off between the similarity of observations and plans, and the likelihood that the agent is performing those plans. We assess the effectiveness of our approach by conducting a comparative experimental evaluation on state-of-the-art benchmarks.

There is a growing need for empirical benchmarks that support researchers and practitioners in selecting the best machine learning technique for given prediction tasks. In this article, we consider the next event prediction task in business process predictive monitoring, and we extend our previously published benchmark by studying the impact on the performance of different encoding windows and of using ensemble schemes. The choice of whether to use ensembles and which scheme to use often depends on the type of data and classification task. While there is a general understanding that ensembles perform well in predictive monitoring of business processes, next event prediction is a task for which no other benchmarks involving ensembles are available. The proposed benchmark helps researchers to select a high-performing individual classifier or ensemble scheme given the variability at the case level of the event log under consideration. Experimental results show that choosing an optimal number of events for feature encoding is challenging, resulting in the need to consider each event log individually when selecting an optimal value. Ensemble schemes improve the performance of low-performing classifiers in this task, such as SVM, whereas high-performing classifiers, such as tree-based classifiers, are not better off when ensemble schemes are considered.