LTLf and LDLf Monitoring: A Technical Report

Runtime monitoring is one of the central tasks to provide operational decision support to running business processes, and check on-the-fly whether they comply with constraints and rules. We study runtime monitoring of properties expressed in LTL on finite traces (LTLf) and in its extension LDLf. LDLf is a powerful logic that captures all monadic second order logic on finite traces, which is obtained by combining regular expressions and LTLf, adopting the syntax of propositional dynamic logic (PDL). Interestingly, in spite of its greater expressivity, LDLf has exactly the same computational complexity of LTLf. We show that LDLf is able to capture, in the logic itself, not only the constraints to be monitored, but also the de-facto standard RV-LTL monitors. This makes it possible to declaratively capture monitoring metaconstraints, and check them by relying on usual logical services instead of ad-hoc algorithms. This, in turn, enables to flexibly monitor constraints depending on the monitoring state of other constraints, e.g., "compensation" constraints that are only checked when others are detected to be violated. In addition, we devise a direct translation of LDLf formulas into nondeterministic automata, avoiding to detour to Buechi automata or alternating automata, and we use it to implement a monitoring plug-in for the PROM suite

A Declarative Framework for Specifying and Enforcing Purpose-aware Policies

Purpose is crucial for privacy protection as it makes users confident that their personal data are processed as intended. Available proposals for the specification and enforcement of purpose-aware policies are unsatisfactory for their ambiguous semantics of purposes and/or lack of support to the run-time enforcement of policies. In this paper, we propose a declarative framework based on a first-order temporal logic that allows us to give a precise semantics to purpose-aware policies and to reuse algorithms for the design of a run-time monitor enforcing purpose-aware policies. We also show the complexity of the generation and use of the monitor which, to the best of our knowledge, is the first such a result in literature on purpose-aware policies.Comment: Extended version of the paper accepted at the 11th International Workshop on Security and Trust Management (STM 2015

Declarative process modeling in BPMN

Traditional business process modeling notations, including the standard Business Process Model and Notation (BPMN), rely on an imperative paradigm wherein the process model captures all allowed activity flows. In other words, every flow that is not specified is implicitly disallowed. In the past decade, several researchers have exposed the limitations of this paradigm in the context of business processes with high variability. As an alternative, declarative process modeling notations have been proposed (e.g., Declare). These notations allow modelers to capture constraints on the allowed activity flows, meaning that all flows are allowed provided that they do not violate the specified constraints. Recently, it has been recognized that the boundary between imperative and declarative process modeling is not crisp. Instead, mixtures of declarative and imperative process modeling styles are sometimes preferable, leading to proposals for hybrid process modeling notations. These developments raise the question of whether completely new notations are needed to support hybrid process modeling. This paper answers this question negatively. The paper presents a conservative extension of BPMN for declarative process modeling, namely BPMN-D, and shows that Declare models can be transformed into readable BPMN-D models. © Springer International Publishing Switzerland 2015

What Automated Planning Can Do for Business Process Management

Business Process Management (BPM) is a central element of today organizations. Despite over the years its main focus has been the support of processes in highly controlled domains, nowadays many domains of interest to the BPM community are characterized by ever-changing requirements, unpredictable environments and increasing amounts of data that influence the execution of process instances. Under such dynamic conditions, BPM systems must increase their level of automation to provide the reactivity and flexibility necessary for process management. On the other hand, the Artificial Intelligence (AI) community has concentrated its efforts on investigating dynamic domains that involve active control of computational entities and physical devices (e.g., robots, software agents, etc.). In this context, Automated Planning, which is one of the oldest areas in AI, is conceived as a model-based approach to synthesize autonomous behaviours in automated way from a model. In this paper, we discuss how automated planning techniques can be leveraged to enable new levels of automation and support for business processing, and we show some concrete examples of their successful application to the different stages of the BPM life cycle

Soft behaviour modelling of user communities

A soft modelling approach for describing behaviour in on-line user communities is introduced in this work. Behaviour models of individual users in dynamic virtual environments have been described in the literature in terms of timed transition automata; they have various drawbacks. Soft multi/agent behaviour automata are defined and proposed to describe multiple user behaviours and to recognise larger classes of user group histories, such as group histories which contain unexpected behaviours. The notion of deviation from the user community model allows defining a soft parsing process which assesses and evaluates the dynamic behaviour of a group of users interacting in virtual environments, such as e-learning and e-business platforms. The soft automaton model can describe virtually infinite sequences of actions due to multiple users and subject to temporal constraints. Soft measures assess a form of distance of observed behaviours by evaluating the amount of temporal deviation, additional or omitted actions contained in an observed history as well as actions performed by unexpected users. The proposed model allows the soft recognition of user group histories also when the observed actions only partially meet the given behaviour model constraints. This approach is more realistic for real-time user community support systems, concerning standard boolean model recognition, when more than one user model is potentially available, and the extent of deviation from community behaviour models can be used as a guide to generate the system support by anticipation, projection and other known techniques. Experiments based on logs from an e-learning platform and plan compilation of the soft multi-agent behaviour automaton show the expressiveness of the proposed model

Semantical Vacuity Detection in Declarative Process Mining

A large share of the literature on process mining based on declarative process modeling languages, like declare, relies on the notion of constraint activation to distinguish between the case in which a process execution recorded in event data “vacuously” satisfies a constraint, or satisfies the constraint in an “interesting way”. This finegrained indicator is then used to decide whether a candidate constraint supported by the analyzed event log is indeed relevant or not. Unfortunately, this notion of relevance has never been formally defined, and all the proposals existing in the literature use ad-hoc definitions that are only applicable to a pre-defined set of constraint patterns. This makes existing declarative process mining technique inapplicable when the target constraint language is extensible and may contain formulae that go beyond pre-defined patterns. In this paper, we tackle this hot, open challenge and show how the notion of constraint activation and vacuous satisfaction can be captured semantically, in the case of constraints expressed in arbitrary temporal logics over finite traces. We then extend the standard automata-based approach so as to incorporate relevance-related information. We finally report on an implementation and experimentation of the approach that confirms the advantages and feasibility of our solution

Handshaking Protocol for Distributed Implementation of Reo

Reo, an exogenous channel-based coordination language, is a model for service coordination wherein services communicate through connectors formed by joining binary communication channels. In order to establish transactional communication among services as prescribed by connector semantics, distributed ports exchange handshaking messages signalling which parties are ready to provide or consume data. In this paper, we present a formal implementation model for distributed Reo with communication delays and outline ideas for its proof of correctness. To reason about Reo implementation formally, we introduce Timed Action Constraint Automata (TACA) and explain how to compare TACA with existing automata-based semantics for Reo. We use TACA to describe handshaking behavior of Reo modeling primitives and argue that in any distributed circuit remote Reo nodes and channels exposing such behavior commit to perform transitions envisaged by the network semantics.Comment: In Proceedings FOCLASA 2014, arXiv:1502.0315

Conformance Checking Based on Multi-Perspective Declarative Process Models

Process mining is a family of techniques that aim at analyzing business process execution data recorded in event logs. Conformance checking is a branch of this discipline embracing approaches for verifying whether the behavior of a process, as recorded in a log, is in line with some expected behaviors provided in the form of a process model. The majority of these approaches require the input process model to be procedural (e.g., a Petri net). However, in turbulent environments, characterized by high variability, the process behavior is less stable and predictable. In these environments, procedural process models are less suitable to describe a business process. Declarative specifications, working in an open world assumption, allow the modeler to express several possible execution paths as a compact set of constraints. Any process execution that does not contradict these constraints is allowed. One of the open challenges in the context of conformance checking with declarative models is the capability of supporting multi-perspective specifications. In this paper, we close this gap by providing a framework for conformance checking based on MP-Declare, a multi-perspective version of the declarative process modeling language Declare. The approach has been implemented in the process mining tool ProM and has been experimented in three real life case studies

Aligning Data-Aware Declarative Process Models and Event Logs

Vastavusanalüüs on haru protsessikaevanduses, mis võimaldab analüütikutel saada aru, kas äriprotsesside sooritused järgivad mudeldatud käitumist. Protsesside mudelid võivad olla nii protseduurilised kui ka deklaratiivsed. Kui protseduurilised mudelid kirjeldavad ära täpsed võimalikud tegevused, siis deklaratiivsed mudelid kirjeldavad reeglid, mis peavad olema protsessi sooritusel olema järgitud. Äriprotsesside täitmiste hoiustamiseks kasutatakse sündmuste logisid. Vastavusanalüüsi meetodid kontrollivad erinevaid protsessi sooritusega seotud vaateid, milleks on juhtimisvoog, andmed ja ressursid. Meetodid, mis käsitlevad endas lisaks juhtimisvoole ka andmeid ning ressursse kutsutakse mitmevaatelisteks või andmeteadlikeks lähenemisteks. Mitmevaatelised meetodid annavad rohkem informatsiooni kõrvalekallete kohta võrreldes juhtimisvoogudel põhinevate meetoditega. Joondustel põhinevad vastavusanalüüsi meetodid on olnud edukad nii juhtimisvool põhinevate kui ka andmeteadlike lähenemiste puhul. On olemas mitmeid joondamisel põhinevaid andmeteadlikke lähenemisi protseduuriliste mudelite jaoks, kuid deklaratiivsete mudelite jaoks need puuduvad.Antud töös on kohandatud olemasolev meetod, mis võimaldab sooritada vastavusanalüüsi andmeteadlike protseduuriliste mudelite puhul, kasutades logide joondustel põhinevat meetodit, võimaldamaks kasutamist ka deklaratiivsetel mudelitel. Deklaratiivsetel mudelitel rakendatav meetod implementeeriti moodulina protsessikaeve keskkonna ProM jaoks ja hinnati implementatsiooni kasutades erinevaid sündmuste logisid.Märksõnad: Protsessikaevandus, Deklaratiivsed protsessimudelid, Andmeteadlik vastavusanalüüs, JoondamineConformance checking, a branch of process mining, allows analysts to determine whether the execution of a business process matches the modeled behavior. Process models can be procedural or declarative. Procedural models dictate the exact behavior that is allowed to execute a specific process whilst declarative models implicitly specify allowed behavior with the rules that must be followed during execution. The execution of a business process is represented by event logs. Conformance checking approaches check various perspectives of a process execution including control-flow, data and resources. Approaches that checks not only the control-flow perspective, but also data and resources are called multi-perspective or data-aware approaches. The approaches provide more deviation information than control-flow based techniques. Alignment based techniques of conformance checking have proved to be advantageous in both control-flow based and data-aware approaches. While there exist several data-aware approaches for procedural process models that are based on the principle of finding alignments, there is none so far for declarative process models. In this thesis, we adapt an existing technique for finding alignments of logs and data-aware procedural models to declarative models. We implemented our approach as a plugin of the process mining framework ProM and evaluated it using event logs with different characteristics.Keywords: Process Mining, Declarative Process Models, Data-aware Conformance checking, Alignmen