432 research outputs found
Declarative Event-Based Workflow as Distributed Dynamic Condition Response Graphs
We present Dynamic Condition Response Graphs (DCR Graphs) as a declarative,
event-based process model inspired by the workflow language employed by our
industrial partner and conservatively generalizing prime event structures. A
dynamic condition response graph is a directed graph with nodes representing
the events that can happen and arrows representing four relations between
events: condition, response, include, and exclude. Distributed DCR Graphs is
then obtained by assigning roles to events and principals. We give a graphical
notation inspired by related work by van der Aalst et al. We exemplify the use
of distributed DCR Graphs on a simple workflow taken from a field study at a
Danish hospital, pointing out their flexibility compared to imperative workflow
models. Finally we provide a mapping from DCR Graphs to Buchi-automata.Comment: In Proceedings PLACES 2010, arXiv:1110.385
An expanded and refined catalog of time patterns for workflows
Trabajos anteriores que definieron catálogos de patrones de control, recursos y datos para workflows tuvieron un rol fundamental en la evolución de esas dimensionesdentro de lenguajes y aplicaciones. Esos patrones han sido usados para evaluar la expresividad de los lenguajes, guiar su evolución, y para establecer una terminología básica que hoy en día es compartida por la mayoría de los desarrolladores de sistemas y lenguajes para workflows. Sin embargo, aún no se han obtenido resultados comparables en la dimensión de tiempo, a pesar de la gran importancia que esta tiene en muchos workflows y procesos de negocio. Aunque recientemente fueron propuestos algunos catálogos de patrones de tiempo, estas propuestas tienen variaslimitaciones en su alcance y en la precisión de las descripciones que los hacen inadecuados para tareas como evaluar lenguajes con respecto a su capacidad parasoportar esos patrones. En este artículo se presenta una aproximación para enfrentar este problema: por una parte, se presenta un catálogo extendido y refinado de patrones de tiempo para workflows; por otra parte, se presenta una formalización de dichos patrones basada en cálculo de eventos y en diagramas de estados, la cual permite hacer una evaluación de la expresividad de los lenguajes con respecto a los patrones y a la dimensión de tiempo
Adaptive Process Management in Cyber-Physical Domains
The increasing application of process-oriented approaches in new challenging cyber-physical domains beyond business computing (e.g., personalized healthcare, emergency management, factories of the future, home automation, etc.) has led to reconsider the level of flexibility and support required to manage complex processes in such domains. A cyber-physical domain is characterized by the presence of a cyber-physical system coordinating heterogeneous ICT components (PCs, smartphones, sensors, actuators) and involving real world entities (humans, machines, agents, robots, etc.) that perform complex tasks in the “physical” real world to achieve a common goal. The physical world, however, is not entirely predictable, and processes enacted in cyber-physical domains must be robust to unexpected conditions and adaptable to unanticipated exceptions. This demands a more flexible approach in process design and enactment, recognizing that in real-world environments it is not adequate to assume that all possible recovery activities can be predefined for dealing with the exceptions that can ensue. In this chapter, we tackle the above issue and we propose a general approach, a concrete framework and a process management system implementation, called SmartPM, for automatically adapting processes enacted in cyber-physical domains in case of unanticipated exceptions and exogenous events. The adaptation mechanism provided by SmartPM is based on declarative task specifications, execution monitoring for detecting failures and context changes at run-time, and automated planning techniques to self-repair the running process, without requiring to predefine any specific adaptation policy or exception handler at design-time
Web Services: A Process Algebra Approach
It is now well-admitted that formal methods are helpful for many issues
raised in the Web service area. In this paper we present a framework for the
design and verification of WSs using process algebras and their tools. We
define a two-way mapping between abstract specifications written using these
calculi and executable Web services written in BPEL4WS. Several choices are
available: design and correct errors in BPEL4WS, using process algebra
verification tools, or design and correct in process algebra and automatically
obtaining the corresponding BPEL4WS code. The approaches can be combined.
Process algebra are not useful only for temporal logic verification: we remark
the use of simulation/bisimulation both for verification and for the
hierarchical refinement design method. It is worth noting that our approach
allows the use of any process algebra depending on the needs of the user at
different levels (expressiveness, existence of reasoning tools, user
expertise)
Indexing the Event Calculus with Kd-trees to Monitor Diabetes
Personal Health Systems (PHS) are mobile solutions tailored to monitoring
patients affected by chronic non communicable diseases. A patient affected by a
chronic disease can generate large amounts of events. Type 1 Diabetic patients
generate several glucose events per day, ranging from at least 6 events per day
(under normal monitoring) to 288 per day when wearing a continuous glucose
monitor (CGM) that samples the blood every 5 minutes for several days. This is
a large number of events to monitor for medical doctors, in particular when
considering that they may have to take decisions concerning adjusting the
treatment, which may impact the life of the patients for a long time. Given the
need to analyse such a large stream of data, doctors need a simple approach
towards physiological time series that allows them to promptly transfer their
knowledge into queries to identify interesting patterns in the data. Achieving
this with current technology is not an easy task, as on one hand it cannot be
expected that medical doctors have the technical knowledge to query databases
and on the other hand these time series include thousands of events, which
requires to re-think the way data is indexed. In order to tackle the knowledge
representation and efficiency problem, this contribution presents the kd-tree
cached event calculus (\ceckd) an event calculus extension for knowledge
engineering of temporal rules capable to handle many thousands events produced
by a diabetic patient. \ceckd\ is built as a support to a graphical interface
to represent monitoring rules for diabetes type 1. In addition, the paper
evaluates the \ceckd\ with respect to the cached event calculus (CEC) to show
how indexing events using kd-trees improves scalability with respect to the
current state of the art.Comment: 24 pages, preliminary results calculated on an implementation of
CECKD, precursor to Journal paper being submitted in 2017, with further
indexing and results possibilities, put here for reference and chronological
purposes to remember how the idea evolve
Formal Object Interaction Language: Modeling and Verification of Sequential and Concurrent Object-Oriented Software
As software systems become larger and more complex, developers require the ability to model abstract concepts while ensuring consistency across the entire project. The internet has changed the nature of software by increasing the desire for software deployment across multiple distributed platforms. Finally, increased dependence on technology requires assurance that designed software will perform its intended function. This thesis introduces the Formal Object Interaction Language (FOIL). FOIL is a new object-oriented modeling language specifically designed to address the cumulative shortcomings of existing modeling techniques. FOIL graphically displays software structure, sequential and concurrent behavior, process, and interaction in a simple unified notation, and has an algebraic representation based on a derivative of the π-calculus. The thesis documents the technique in which FOIL software models can be mathematically verified to anticipate deadlocks, ensure consistency, and determine object state reachability. Scalability is offered through the concept of behavioral inheritance; and, FOIL’s inherent support for modeling concurrent behavior and all known workflow patterns is demonstrated. The concepts of process achievability, process complete achievability, and process determinism are introduced with an algorithm for simulating the execution of a FOIL object model using a FOIL process model. Finally, a technique for using a FOIL process model as a constraint on FOIL object system execution is offered as a method to ensure that object-oriented systems modeled in FOIL will complete their processes based activities. FOIL’s capabilities are compared and contrasted with an extensive array of current software modeling techniques. FOIL is ideally suited for data-aware, behavior based systems such as interactive or process management software
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