To identify the causes of performance problems or to predict process behavior, it is essential to have correct and complete event data. This is particularly important for distributed systems with shared resources, e.g., one case can block another case competing for the same machine, leading to inter-case dependencies in performance. However, due to a variety of reasons, real-life systems often record only a subset of all events taking place. To understand and analyze the behavior and performance of processes with shared resources, we aim to reconstruct bounds for timestamps of events in a case that must have happened but were not recorded by inference over events in other cases in the system. We formulate and solve the problem by systematically introducing multi-entity concepts in event logs and process models. We introduce a partial-order based model of a multi-entity event log and a corresponding compositional model for multi-entity processes. We define PQR-systems as a special class of multi-entity processes with shared resources and queues. We then study the problem of inferring from an incomplete event log unobserved events and their timestamps that are globally consistent with a PQR-system. We solve the problem by reconstructing unobserved traces of resources and queues according to the PQR-model and derive bounds for their timestamps using a linear program. While the problem is illustrated for material handling systems like baggage handling systems in airports, the approach can be applied to other settings where recording is incomplete. The ideas have been implemented in ProM and were evaluated using both synthetic and real-life event logs.
翻译:为了查明业绩问题的原因或预测过程行为,必须具备正确和完整的事件数据。这对于分布式系统具有共享资源,这特别重要,例如,一个案件可以阻止另一个案件竞争同一机器,导致业绩方面的跨案件依赖性;然而,由于各种原因,实际生活系统往往只记录所有正在发生的事件的子集;为了理解和分析使用共享资源的过程的行为和绩效,我们的目标是在一定情况下重建事件时间戳的界限,但对于系统内其他案件的事件则没有推断记录。我们在事件日志和进程模型中系统地引入多实体概念,从而形成并解决问题。然而,由于多种原因,实际生活系统往往只记录所有事件的一个子集。我们把PQR系统定义为具有共享资源和排队方式的多实体进程的特殊类别。我们随后研究从一个不完整的事件日志中推断出的问题,而没有记录系统中的其他事件。我们制定和解决问题的方法是:在事件日志中采用不完善的时间戳,同时在系统内,我们用系统内系统内部流程和在线处理系统里,我们用系统里程来进行系统里算。