A practical data-flow verification scheme for business processes

Data in business processes becomes more and more important. Current standard languages for process modeling like BPMN 2.0 which include the data flow reflect this. Ensuring the correctness of the data flow in processes is challenging. Model checking, i.e., verifying properties of process models, is a well-known technique to this end. An important part of model checking is the construction of the state space of the model. However, state-space explosion typically is in the way of an effective verification. We study how to overcome this problem in our context by means of reduction. More specifically, we propose a reduction on the level of the process model. To our knowledge, this is new for the data-flow analysis of processes. The core of our approach are so-called regions of the process model that are relevant for the verification of properties describing the data flow. Non-relevant regions are candidates for reduction of the process model, yielding a smaller state space. Our evaluation shows that our approach works well on industrial process models.     

Digital twin-based assembly data management and process traceability for complex products

Complex products such as satellites, missiles, and aircraft typically have demanding requirements for dynamic data management and process traceability. The assembly process for these complex products involves high complexity, strong dynamics, many uncertainties, and frequent rework and repair, especially in the model development stage. Achieving assembly data management and process traceability for complex products has always been a challenge. A recently proposed solution involves one-to-one mapping of the corresponding physical entity, also known as the digital twin method. This paper proposes a digital twin-based assembly data management and process traceability approach for complex products. First, the dynamic evolutionary process of complex product assembly data was analyzed from three dimensions: granularity, period and version. Then, a framework of digital twin-based assembly data management and process traceability for complex products was constructed. Some core techniques are: 1) workflow-based product assembly data organization and version management; 2) synchronous modeling of the product assembly process based on digital twin; and 3) hierarchical management and traceability of product assembly data based on digital twin. On this basis, an algorithm flowchart for generating a product assembly data package was created, which includes product assembly data management, assembly process traceability, and generation of a product assembly data package. Furthermore, the Digital Twin-based Assembly Process Management and Control System (DT-APMCS) was designed to verify the efficiency of the proposed approach. Some aerospace-related assembly enterprises are currently using DT-APMCS and achieving satisfactory results. Finally, a summary of our work is given, and the future research work is also discussed.     

A new verification technique for large processes based on identification of relevant tasks

Verification recently has become a challenging topic for business process languages. Verification techniques like model checking allow to ensure that a process complies with domain-specific requirements, prior to the execution. To execute full-state verification techniques like model checking, the state space of the process needs to be constructed. This tends to increase exponentially with the size of the process schema, or it can even be infinite. We address this issue by means of requirements-specific reduction techniques, i.e., reducing the size of the state space without changing the result of the verification. We present an approach that, for a given requirement the system must fulfill, identifies the tasks relevant for the verification. Our approach then uses these relevant tasks for a reduction that confines the process to regions of interest for the verification. To evaluate our new technique, we use real-world industrial processes and requirements. Mainly because these processes make heavy use of parallelization, full-state-search verification algorithms are not able to verify them. With our reduction in turn, even complex processes with many parallel branches can be verified in less than 10 s.     

Evaluating the performance of a discrete manufacturing process using RFID: A case study

The material flow is a major focus point in improving productivity in today’s product diversified manufacturing organizations. Nevertheless, there is still a lack of efficient methods to control material flow through manufacturing processes in cases where multi-item tracking is difficult to achieve. This paper presents an RFID-based RTLS (Real-Time Location System) solution for obtaining multi-item work-in-process visibility within a manufacturer. It delivers detailed performance metrics through RTLS data analysis in order to evaluate workflow performance and to obtain a lean process. We pre-filter the RTLS data through the development of a middleware data collection method to acquire near real-time performance evaluation. A case study illustrates the complete process including measurements before and after a workflow redesign. The increased level of detail from RFID measurements yields new insights into shop floor actions and the real effects of redesign efforts.     

Streamlining patient consultations for sleep disorders with a knowledge-based CDSS

ObjectivesThis paper examines the workflow of sleep physicians during a patient consultation and how an innovative clinical decision support system (CDSS) provides efficiency and effectiveness gains.MethodsThe CDSS tools consisted of two input applications for patient data, with a knowledge based decision support system developed participatively with physicians and an international panel. An argument tree approach was used to produce diagnostic explanations and an evidence-based report for the physician using medically correct and shared terminology. A usability evaluation using a qualitative approach was carried out to ensure that the CDSS met the physicians׳ information needs, as well as the wider needs of a Sleep Investigation Unit.ResultsThe physicians found the CDSS both useful and usable with clear applications in triage and diagnostic decision-making, and in patient education.ConclusionThe CDSS both reduces the time and number of visits needed for consultations, and helps focus consultation on better individual patient care through informed explanation of diagnostic and treatment decisions.     

A linear time layout algorithm for business process models

The layout of a business process model influences how easily it can be understood. Existing layout features in process modeling tools often rely on graph representations, but do not take the specific properties of business process models into account. In this paper, we propose an algorithm that is based on a set of constraints which are specifically identified toward establishing a readable layout of a process model. Our algorithm exploits the structure of the process model and allows the computation of the final layout in linear time. We explain the algorithm, show its detailed run-time complexity, compare it to existing algorithms, and demonstrate in an empirical evaluation the acceptance of the layout generated by the algorithm. The data suggests that the proposed algorithm is well perceived by moderately experienced process modelers, both in terms of its usefulness as well as its ease of use.     

Designing like a Pro: The automated composition of workflow activities

To design a workflow process that is efficient, meaningful, and understandable it is important to properly consider how to compose the activities it will consist of. In this paper, guidelines are presented for this exact purpose. These focus on the elementary data-processing steps that are at the core of a workflow process. The guidelines help to determine the relative importance of these data-processing steps as well as their relatedness, such that activities can be composed in a fully automated manner. We implemented this approach in freely available software. A thorough evaluation that incorporates real-life workflow designs indicates that the use of these guidelines leads to activities that closely resemble those designed by experienced modelers. As such, the proposed guidelines provide a proper and automated alternative to what is otherwise a complex and time-consuming task.     

Property specification,process verification,and reporting – A case study with vehicle-commissioning processes

Testing in the automotive industry is supposed to guarantee that vehicles are shipped without any flaw. Respective processes are complex, due to the variety of components and electronic devices in modern vehicles. To achieve error-free processes, their formal analysis is required. Specifying and maintaining properties the processes must satisfy in a user-friendly way is a core requirement on any verification system. We have observed that there are few property templates that testing processes must adhere to, and we describe these templates. They depend on the context of the processes, e.g., the components of the vehicle or testing stations. We have developed a framework that instantiates the templates of properties at verification time and then verifies the process against these instances. To allow an automatic verification we develop a transformation of the commissioning process to a Petri net. Using a novel approach, we are able to report the found violations to the user in a user-friendly way. Our empirical evaluation with the industrial partner has shown that our framework does detect property violations in processes. From expert interviews we conclude that our framework is user-friendly and well suited to operate in a real production environment.     

Development of a computationally efficient semi-distributed hydrologic modeling application for soil moisture,lateral flow and runoff simulation

A new automated workflow based computationally efficient hydrologic modeling application is developed for soil moisture and runoff simulation. The spatially distributed conceptual framework underpinning the Soil Moisture And Runoff simulation Toolkit (SMART) resolves water balance in large upland catchments where topography and land cover are significant drivers of rainfall-runoff transformations. SMART's computational efficiency is achieved by delineation of contiguous and topologically connected hydrologic response units and solving the water balance equation on spatially representative Equivalent Cross-Sections (ECSs). ECSs are formulated by aggregating topographic and physiographic properties of the complete or part of the first order Strahler sub-basins, thereby reducing the number of computational elements. Water balance simulations across the ECSs in two sub-basins illustrated little loss of accuracy compared to the distributed cross section delineations and soil moisture observations. A 2-dimensional Richards' equation based hydrologic model in SMART can be augmented with additional functionalities or replaced with other model structures.     

Improving workflow modularity using a concern-specific layer on top of Unify

Workflows are a popular means of automating processes in many domains, ranging from high-level business process modeling to lower-level web service orchestration. However, state-of-the-art workflow languages offer a limited set of modularization mechanisms. This results in monolithic workflow specifications, in which different concerns are scattered across the workflow and tangled with one another. This hinders the design, evolution, and reusability of workflows expressed in these languages. We address this problem through the Unify framework. This framework enables uniform modularization of workflows by supporting the specification of all workflow concerns – including crosscutting ones – in isolation of each other. These independently specified workflow concerns are connected to each other using workflow-specific connectors. In order to further facilitate the development of workflows, we enable the definition of concern-specific languages (CSLs) on top of the Unify framework. A CSL facilitates the expression of a family of workflow concerns by offering abstractions that map well to the concerns' domain. Thus, domain experts can add concerns to a workflow using concern-specific language constructs. We exemplify the specification of a workflow in Unify, and show the definition and application of two concern-specific languages built on top of Unify.