Why Am I Waiting? Analyzing Waiting Times in Business Processes from Event Logs (Extended Abstract) Muhammad Awais Ali University of Tartu, Tartu, Estonia muhammad.awais.ali@ut.ee Abstract—Business analysts are in a continuous effort to the unimportant tasks suffer the most and hence, their improve the cycle time of a process by identifying waiting waiting time increases [11]. time bottlenecks and adapting strategies to improve the business processes by reducing delays. However, there are several sources In this setting, the problem addressed in this thesis is two- of waiting times. Therefore, it is a challenge for a business fold. First, the thesis addresses the challenge of identifying analyst to categorize and quantify the sources of waiting time and the internal sources of waiting time from an event log of discover changes that may reduce or eliminate these delays. We a business process, and quantifying the share of waiting will empirically address this research problem by first identifying time attributable to each of these internal sources. Second, the sources of waiting time from the process execution logs and quantifying the share of waiting time attributable to each of the it addresses the problem of recommending interventions to sources. Secondly, we will identify the interventions to reduce or reduce the waiting time. Accordingly, the research questions eliminate the waiting time in business processes. Our proposed of this study are: approach will be evaluated in two phases. In the first phase, it 1) What are the possible sources of waiting time in a will be evaluated using BPI challenges, and in the second phase, business process (e.g. batching, prioritization, etc.)? we will conduct a case study with industrial partners to further validate our approach. 2) How to automatically detect the sources of waiting time Index Terms—Waiting Time, Process Mining, Event Logs. from an event log? 3) How to recommend interventions in view of minimizing I. I NTRODUCTION AND P ROBLEM D EFINITION the amount of waiting time? Reducing delays in business processes is a recurrent prob- A solution should fulfil the following requirements: lem in the field of business process management. To ad- R1: The recommended interventions should be accurate. dress this problem, analysts need to discover and quantify Accuracy can be measured in terms of the error between the the sources of waiting time in a process and then design predicted and the actual outcome after the intervention. interventions to mitigate them. The sources of waiting time R2: The proposed approach should recommend interven- are manifold [1], [2]. Some sources of waiting are external tions in an acceptable computation time. to the process (e.g. waiting for a response from a customer, The outcome of this research will be a set of techniques waiting for a delivery from a supplier) [3]. Others are due to that take event log of a business process as an input, produces factors internal to the process, including but not limited to: a diagnostic of the causes of waiting time and recommends 1) Resource Contention: Resource contention occurs actions to reduce or eliminate the waiting time in a business when there is more work to be done than the resources process as illustrated in Figure 1. available to accomplish it [4]. 2) Batch Processing: In batch processing [5]–[8], re- sources bundle several cases together so that they can be processed as a group. This will infuse waiting time since the resource will wait for a batch to be available for processing. Hence, this introduces waiting time due to batch creation. 3) Resource Unavailability: A particular resource in a business process that does not operate on weekends will eventually introduce the waiting time in a process due to resource unavailability [9], [10]. 4) Work Prioritization: There may be some tasks in a Fig. 1. Illustrative Example process that the resource may prioritize to improve the throughput of the process. However, the benefit II. M ETHODOLOGY decreases with an increase in prioritization, such as The proposed research will adopt Design Science Research Work funded by the European Research Council (PIX Project). (DSR) [12] for identifying the sources for the delay in a Copyright © 2021 for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0). business process. We will follow an iterative approach con- combination of possible interventions to reduce the waiting sisting of design, prototyping, and evaluation. We will start time in the process, taking into consideration constraints on by conducting a systematic literature review of sources of other performance measures, such as cost. The impact of delays and waiting waste in business processes, drawing for these interventions will be evaluated by means of data-driven example into the literature on Lean management [1], [13]. simulation techniques [14], [15]. Based on this review, we will develop a taxonomy of sources of waiting time in business processes. This analysis will inform the development of a framework for identifying sources of waiting waste in a process based on execution data. We will then develop techniques to quantify the share of waiting time attributable to each of the sources identified in the taxonomy and to recommend interventions to reduce or eliminate the waiting time. The proposed framework evaluation will be in two phases. In the first phase, we will evaluate our approach using synthetic event logs as well as real-life event logs, such as those released by the BPI challenge series.1 In this setting, we will compare the findings of our proposed techniques with those of the participants in these challenges. Based on Fig. 2. Overall Research Design the insights gained from this first evaluation phase, we will improve our proposed approach. We will then conduct a case study in a real setting in order to further validate our approach R EFERENCES in a second phase. [1] J. Dinis-Carvalho, F. Moreira, S. Bragança, E. Costa, A. Alves, and R. Sousa, “Waste identification diagrams,” Production Planning & III. A PPROACH Control, vol. 26, no. 3, pp. 235–247, 2015. [2] S. Suriadi, C. Ouyang, W. M. van der Aalst, and A. H. ter Hofstede, Enterprise systems record events corresponding to an exe- “Event interval analysis: Why do processes take time?” Decision Support Systems, vol. 79, pp. 77–98, 2015. cution of a task. 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