Towards a compendium of process technologies: The jBPT library for process model analysis

This paper presents the idea of a compendium of process technologies, i.e., a concise but comprehensive collection of techniques for process model analysis that support research on the design, execution, and evaluation of processes. The idea originated from observations on the evolution of process-related research disciplines. Based on these observations, we derive design goals for a compendium. Then, we present the jBPT library, which addresses these goals by means of an implementation of common analysis techniques in an open source codebase

Isotactics as a foundation for alignment and abstraction of behavioral models

There are many use cases in business process management that require the comparison of behavioral models. For instance, verifying equivalence is the basis for assessing whether a technical workflow correctly implements a business process, or whether a process realization conforms to a reference process. This paper proposes an equivalence relation for models that describe behaviors based on the concurrency semantics of net theory and for which an alignment relation has been defined. This equivalence, called isotactics, preserves the level of concurrency of aligned operations. Furthermore, we elaborate on the conditions under which an alignment relation can be classified as an abstraction. Finally, we show that alignment relations induced by structural refinements of behavioral models are indeed behavioral abstractions

How do users design scientific workflows? The Case of Snakemake

Scientific workflows automate the analysis of large-scale scientific data, fostering the reuse of data processing operators as well as the reproducibility and traceability of analysis results. In exploratory research, however, workflows are continuously adapted, utilizing a wide range of tools and software libraries, to test scientific hypotheses. Script-based workflow engines cater to the required flexibility through direct integration of programming primitives but lack abstractions for interactive exploration of the workflow design by a user during workflow execution. To derive requirements for such interactive workflows, we conduct an empirical study on the use of Snakemake, a popular Python-based workflow engine. Based on workflows collected from 1602 GitHub repositories, we present insights on common structures of Snakemake workflows, as well as the language features typically adopted in their specification

Monotone Precision and Recall Measures for Comparing Executions and Specifications of Dynamic Systems

The behavioural comparison of systems is an important concern of software engineering research. For example, the areas of specification discovery and specification mining are concerned with measuring the consistency between a collection of execution traces and a program specification. This problem is also tackled in process mining with the help of measures that describe the quality of a process specification automatically discovered from execution logs. Though various measures have been proposed, it was recently demonstrated that they neither fulfil essential properties, such as monotonicity, nor can they handle infinite behaviour. In this paper, we address this research problem by introducing a new framework for the definition of behavioural quotients. We proof that corresponding quotients guarantee desired properties that existing measures have failed to support. We demonstrate the application of the quotients for capturing precision and recall measures between a collection of recorded executions and a system specification. We use a prototypical implementation of these measures to contrast their monotonic assessment with measures that have been defined in prior research

Photonic candle – focusing light using nano-bore optical fibers

Focusing light represents one of the fundamental optical functionalities that is used in a countless number of situations. Here we introduce the concept of nano-bore optical fiber mediated light focusing that allows to efficiently focus light at micrometer distance from the fiber end face. Since the focusing effect is provided by the fundamental fiber mode, device implementation is extremely straightforward since no post-processing or nano-structuring is necessary. Far-field measurements on implemented fibers, simulations, and a dual-Gaussian beam toy model confirm the validity of the concept. Due to its unique properties such as strong light localization, a close to 100% implementation success rate, extremely high reproducibility, and its compatibility with current fiber circuitry, the concept will find application in numerous areas that demand to focus at remote distances