Andreas Lanz

Workflow Time Patterns for Process-Aware Information Systems

Formal specification and operational support of time constraints constitute fundamental challenges for any process-aware information system. Although temporal constraints play an important role in the context of long-running business processes, time support is limited in existing process management systems. By contrast, different kinds of planning tools (e.g., calendar systems, project management tools) provide more sophisticated facilities for handling task-related time constraints, but lack operational support for business processes. This paper presents a set of time patterns to foster systematic design and comparison of the different technologies in respect to the time perspective. These time patterns are all based on empirical evidence from several large case studies. Their widespread use will contribute to further maturation of process-aware information systems and related evaluation schemes.

Time patterns for process-aware information systems

Companies increasingly adopt process-aware information systems (PAISs) due to their promising perspectives for improved business process support. Although the proper handling of temporal constraints is crucial in this context, existing PAISs vary significantly regarding their support of the temporal perspective of a business process. To make PAISs comparable with respect to their ability to deal with temporal constraints and to facilitate the development of a time-aware PAIS, this paper suggests 10 time patterns. All patterns are based on empirical evidence we gathered in case studies. Additionally, they are validated through a systematic literature review. Based on the time patterns, we then provide an in-depth evaluation of selected PAISs and academic approaches. Altogether, the 10 time patterns will not only facilitate the selection of technologies for realizing time- and process-aware information systems but can also be used as reference for implementing time support in PAISs.

Robust and Flexible Error Handling in the AristaFlow BPM Suite

Process-aware information systems will be not accepted by users if rigidity or idleness due to failures comes with them. When implementing business processes based on process management technology one fundamental goal is to ensure robustness of the resulting process-aware information system. Meeting this goal becomes extremely complicated if high flexibility demands need to be fulfilled. This paper shows how the AristaFlow BPM Suite assists process participants in coping with errors and exceptional situations in a flexible and robust way. In particular, we focus on novel error handling procedures and capabilities using the flexibility provided by ad-hoc changes not shown in other context so far.

From ADEPT to AristaFlow BPM Suite: A Research Vision Has Become Reality

During the last decade we have developed the ADEPT next generation process management technology. Its features and its different prototype versions attracted a number of companies. However, an enterprise cannot base the implementation of its process-aware information system (PAIS) on an experimental prototype, especially if maintenance and further development are not assured. At the beginning of 2008, therefore, we founded a spin-off as joint venture with industrial partners to transfer ADEPT into an industrial-strength product version called AristaFlow BPM Suite, and to provide maintenance support for it. The product version is now available for academic and industrial use.

Controllability of Time-Aware Processes at Run Time

Companies increasingly adopt process-aware information systems (PAISs) to analyze, coordinate, and monitor their business processes. Although the proper handling of temporal constraints (e.g., deadlines, minimum time lags between activities) is crucial for many applications, contemporary PAISs lack a sophisticated support of the temporal perspective of business processes. In previous work, we introduced Conditional Simple Temporal Networks with Uncertainty (CSTNU) for checking controllability of time constraint networks with decision points. In particular, controllability refers to the ability of executing a time constraint network independent of the actual duration of its activities, while satisfying all temporal constraints. In this paper, we demonstrate how CSTNUs can be applied to time-aware business processes in order verify their controllability at design as well as at run time. In particular, we present an algorithm for ensuring the controllability of time-aware process instances during run time. Overall, proper run-time support of time-aware business processes will broaden the use of PAIS significantly.

Process time patterns

Companies increasingly adopt process-aware information systems (PAISs) to model, execute, monitor, and evolve their business processes. Though the handling of temporal constraints (e.g., deadlines or time lags between activities) is crucial for the proper support of business processes, existing PAISs vary significantly regarding the support of the temporal perspective. Both the formal specification and the operational support of temporal constraints constitute fundamental challenges in this context. In previous work, we introduced process time patterns, which facilitate the comparison and evaluation of PAISs in respect to their support of the temporal perspective. Furthermore, we provided empirical evidence for these time patterns. To avoid ambiguities and to ease the use as well as the implementation of the time patterns, this paper formally defines their semantics. To additionally foster the use of the patterns for a wide range of process modeling languages and to enable pattern integration with existing PAISs, the proposed semantics are expressed independently of a particular process meta model. Altogether, the presented pattern formalization will be fundamental for introducing the temporal perspective in PAISs. HighlightsA formal semantics for process time patterns based on execution traces is presented.The defined semantics is independent of any process modeling language or paradigm.Implementation of the time patterns based on the formal semantics.

Enabling Personalized Process Schedules with Time-Aware Process Views

Summary.Companies increasingly adopt process-aware information systems (PAISs) to model, enact, monitor, and evolve their business processes. Although the proper handling of temporal constraints (e.g., deadlines and minimum time lags between activities) is crucial for many application domains, existing PAISs vary significantly regarding the support of the temporal perspective of a business process. In previous work, we introduced characteristic time patterns for specifying the temporal perspective of PAISs. However, time-aware process schemas might be complex and hard to understand for end-users. To enable their proper visualization, therefore, this paper introduces an approach for transforming time-aware process schemas into enhanced Gantt charts. Based on this, a method for creating personalized process schedules using process views is suggested. Overall, the presented approach enables users to easily understand and monitor time-aware processes in PAISs.

A formal semantics of time patterns for process-aware information systems

Companies increasingly adopt process-aware information systems (PAISs) to coordinate, monitor and evolve their business processes. Although the proper handling of temporal constraints (e.g., deadlines and minimum time lags between activities) is crucial in many application domains, existing PAISs vary significantly regarding their support of the temporal perspective of business processes. Both the formal specification and operational support of temporal constraints constitute fundamental challenges in this context. In previous work, we introduced time patterns facilitating the comparison of PAISs in respect to their support of the temporal perspective and provided empirical evidence for them. To avoid ambiguities and to ease the use as well as implementation of the time patterns, this paper formally defines their semantics. To enable pattern use in a wide range of process modeling languages and pattern integration with existing PAISs, this semantics is expressed independent of a particular process meta model. Altogether, the presented pattern formalization will foster the integration of the temporal perspective in PAISs.

Optimized Time Management for Declarative Workflows

Declarative process models are increasingly used since they fit better with the nature of flexible process-aware information systems and the requirements of the stakeholders involved. When managing business processes, in addition, support for representing time and reasoning about it becomes crucial. Given a declarative process model, users may choose among different ways to execute it, i.e., there exist numerous possible enactment plans, each one presenting specific values for the given objective functions (e.g., overall completion time). This paper suggests a method for generating optimized enactment plans (e.g., plans minimizing overall completion time) from declarative process models with explicit temporal constraints. The latter covers a number of well-known workflow time patterns. The generated plans can be used for different purposes like providing personal schedules to users, facilitating early detection of critical situations, or predicting execution times for process activities. The proposed approach is applied to a range of test models of varying complexity. Although the optimization of process execution is a highly constrained problem, results indicate that our approach produces a satisfactory number of suitable solutions, i.e., solutions optimal in many cases.

Dealing with Changes of Time-Aware Processes

The proper handling of temporal process constraints is crucial in many application domains. Contemporary process-aware information systems (PAIS), however, lack a sophisticated support of time-aware processes. As a particular challenge, the execution of time-aware processes needs to be flexible as time can neither be slowed down nor stopped. Hence, it should be possible to dynamically adapt time-aware process instances to cope with unforeseen events. In turn, when applying such dynamic changes, it must be re-ensured that the resulting process instances are temporally consistent; i.e., they still can be completed without violating any of their temporal constraints. This paper presents the ATAPIS framework which extends well established process change operations with temporal constraints. In particular, it provides pre- and post-conditions for these operations that guarantee for the temporal consistency of the changed process instances. Furthermore, we analyze the effects a change has on the temporal properties of a process instance. In this context, we provide a means to significantly reduce the complexity when applying multiple change operations. Respective optimizations will be crucial to properly support the temporal perspective in adaptive PAIS.