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

Enhancing BPMN Conformance Checking with OR Gateways and Data Objects

Äriprotsessimudel ja -notatsioon (BPMN) on arenev standard äriprotsesside graafiliseks kujutamiseks. Protsessimudel kirjeldab, kuidas äriprotsess peaks toimima. Kui äriprotsessi tegelikust käitamisest on saadaval ka sündmuste logi, on võimalik vastata küsimusele, kas protsessimudel vastab tegelikkusele. Vastavusanalüüs püüab tuvastada mittevastavusi protsessimudeli ja äriprotsessi käitamisel tekkinud sündmuste logi vahel. BPMN vastavuseanalüsaator on üks Itaalia ettevõtte SIAV-i poolt arendatud protsessikaeve tööriista osadest. Nimetatud tööriistal on aga puudujäägid formaalse semantika osas. Nimelt keskendub vastavusanalüüs järgnevuse voole (control-flow) protsessis, kuid jätab arvesse võtmata andmetevahelisi sõltuvusi. Lisaks ei ole vastavusanalüüsil võimalik kasutada protsessimudeleid, mis sisaldavad OR väravaid (OR gateway). OR-join omab mitme-tähenduslikku semantikat. Se lle konstruktsiooni jaoks on pakutud mitmeid formaalseid semantikaid sarnastes keeltes, nagu EPCs ja YAWL. Nimetatud semantikate kasutatamine mudelite käitamisel ja vastavuse analaüüsil on aga arvutuslikult kulukas. Seega on käesolevas lõputöös implementeeritud OR värava aktiveerimine lineaarse ajalise sõltuvusega mudeli suuruse suhtes. Kuna SIAV-i vastavusanalüsaator ei võta arvesse andmetevahelisi sõltuvusi, võib puudulik analüüs viia vigase vastavusdiagnostikani. Näiteks võib andmeatribuut anda infot selle kohta, et käitati vale tegevus. Kirjeldatud põhjustel ei peaks vastavusanalüsaator tegelema vaid järgnevuse voo vastavuse analüüsiga, vaid peaks arvesse võtma ka andmeid ja nendevahelisi sõltuvusi ning aega. Käesoleva töö teises osas täiendati olemasolevat andmeanalüsaatorit andmeatribuutidega.The Business Process Model and Notation is a developing standard for capturing business processes. Process models describe how the business process is expected to be executed. When a log is available from process executions, this situation raises the interesting question “Are the model and the log conformant?". Conformance checking, also referred to as conformance analysis, aims at the detection of inconsistencies between a process model and its corresponding execution log.The BPMN conformance checker, as a part of a process mining tool, developed an Italian company called SIAV, however, this tool lacks some formal semantics. In particular, the previous conformance checking approach in SIAV tends to focus on the control-flow in a process, while abstracting from data dependencies and process models containing OR gateways could not be used.OR-join has an ambiguous semantics. The several formal semantics of this construct have been proposed for similar languages such as EPCs and YAWL. However, executing and verifying models using these semantics is computationally expensive. Therefore, in this thesis, we implemented enablement of an OR-join in linear time in the size of the workflow graph.Data dependencies are also not considered in conformance checker developed in SIAV, which may lead to misleading conformance diagnostics. For example, a data attribute may provide strong evidence that the wrong activity was executed. That’s why the conformance checker should not only describe the process behaviour from the control flow point of view, but also from other perspectives like data or time. In the second part of the thesis, we enhanced the existing conformance checker with data attributes

Dealing with Complex Parallel Structures in Process Discovery

Üks protsessikaeve eesmärkidest on leida protsessimudeleid logifailidest. Samas sõltub leitava protsessimudeli kvaliteet sellest, kui täielik informatsioon protsessi käitumise kohta logifailis on, kuna paralleelarvutuste keerukuse kasv on faktoraalses sõltuvuses harude hulgast. Selles lõputöös tutvustatakse uut algoritmi, mis kombineerib jaga-ja-valitse võtet olemasolevate kaevealgoritmidega, et täiustada hästistruktureeritud ja samaaegselt toimuvate tegumitega protsessimudelite kaevet poolikutest logifailidest. See töö kirjeldab väljapakutud algoritmi ja selgitab, kuidas see töötab samm-sammu haaval illustratiivsete kaeveprotsessi näidete abil. Lõpuks hindame selle meetodi efektiivsust ja tulemuslikkust kasutades protsessimudeleid, mis sisaldavad samaaegselt toimuvaid tegumeid ja juhuslikult loodud mudeleid.One of the aims of process mining is to discover a process model from a log. However, the quality of the discovered model depends on the completeness of the information about the process behaviour contained in the log. Incomplete logs do not provide all the possible behaviours. Existing process discovery algorithms dealing with incomplete logs, have troubles when working with complex parallel structures, because parallel behaviour has factorial rate of growth with respect to the number of branches. In this work, a new algorithm is proposed, which combines divide and conquer approach, with the existing mining algorithms to improve discovery of highly structured and highly concurrent process models from incomplete logs. This work describes the proposed algorithm, and explains how it works with illustrative step-by-step examples of the mining procedure. Finally, we evaluate the effectiveness and efficiency of our approach by using process models containing complex parallel structures and randomly generated models

Conformance Checking of Mixed-paradigm Process Models

Mixed-paradigm process models integrate strengths of procedural and declarative representations like Petri nets and Declare. They are specifically interesting for process mining because they allow capturing complex behaviour in a compact way. A key research challenge for the proliferation of mixed-paradigm models for process mining is the lack of corresponding conformance checking techniques. In this paper, we address this problem by devising the first approach that works with intertwined state spaces of mixed-paradigm models. More specifically, our approach uses an alignment-based replay to explore the state space and compute trace fitness in a procedural way. In every state, the declarative constraints are separately updated, such that violations disable the corresponding activities. Our technique provides for an efficient replay towards an optimal alignment by respecting all orthogonal Declare constraints. We have implemented our technique in ProM and demonstrate its performance in an evaluation with real-world event logs.Comment: Accepted for publication in Information System

A hybrid approach for aspect-oriented business process modeling

Separation of concerns has long been an important strategy to deal with complexity when developing a system. Some concerns (like security) are scattered through the whole system, and different modules are tangled to such concerns. These concerns are known as cross-cutting concerns. When the system in question is a business process, cross-cutting concerns are aimed at being encapsulated by Aspect-Oriented Business Process Modeling. However, the state-of-the-art techniques in this field lack efficient mechanisms that (1) support composition of cross-cutting concerns that can be defined in parallel to (a part of) a process model and (2) enable specifying both mandatory and optional cross-cutting concerns. To address these limitations, this paper proposes a new Aspect-Oriented Business Process Modeling approach. The approach is hybrid since it is based on declarative rules to relate imperative cross-cutting concerns and imperative business process models. The approach is explained, formally grounded with precise semantics, and used accordingly to implement the artifacts that support modeling and enactment of business processes in the proposed fashion as a proof of concept. In addition, the approach is evaluated on the basis of the Technology Acceptance Model during a workshop session. The result shows that participants perceived the approach usable and easy to use

Discovery and Evaluation of Coordination Patterns for Business Processes in many-to-many Relationships

Today, organisations use process-oriented systems to manage and automate the enactment of their business processes. The cornerstone artifact is the process model, which at design-time is used to describe the steps that need to be fulfilled in order to reach a business goal. At run-time, the process model is executed and process instances are created. The existing modelling approaches are based on three main paradigms: the more traditional activity-centric paradigm, the case handling paradigm and the more recent data-centric paradigm. Process models can be classified into monolithic and interacting process models. Monolithic process models are predominantly created in the activity-centric and case-handling paradigm. In a monolithic process model, all the involved resources and activities are contained in one vast model. In monolithic process models, interactions occur between the different partners involved in a cross-organisational setting which exchange messages with one another. Interacting process models are prevalent in the data-centric paradigm. In interacting process models, interdependent processes interact with one another such that on a meta-level a composite business process is achieved. In both types of models, interactions between interrelated processes need to be properly coordinated such that a common business objective can be reached. Handling the complexity generated by highly interconnected scenarios, involving hundreds of processes, is a challenge in business process management. Process management systems for such collaborations must be capable of handling both synchronous and asynchronous process interactions. In the context of process management systems, different pattern catalogues such as the Service Interaction Pattern or Correlation Pattern have been used for describing fundamental types of interactions that repeatedly arise during business process modelling. Yet, until now, none of the existing pattern catalogues has explicitly tackled the interactions of heterogeneous business processes in a many-to-many relationship setting. Furthermore, the existing pattern catalogues for the interaction-perspective are not paradigm independent, but mainly focus on the activity-centric paradigm. For modelling multiple interacting processes with different dependency constraints, a collection of patterns that explicitly describes interactions among processes in different types of relationships, in a paradigm-independent manner, is required. This thesis proposes a catalogue of patterns, named the Process Coordination Patterns, describing process interactions in a one-to-many and many-to-many relationship setting. In the developed pattern catalogue, the discovered seven patterns are illustrated by abstracting from any specific paradigm. The PCPs may be used as guidance for evaluating the degree to which existing approaches capture more complex process interactions. In this thesis, the proposed pattern catalogue is put into practice by evaluating the degree to which two modelling approaches, based on different paradigms, can support the seven Process Coordination Patterns

Artifact-centric business process models in UML : specification and reasoning

Business processes are directly involved in the achievement of an organization's goals, and for this reason they should be performed in the best possible way. Modeling business processes can help to achieve this as, for instance, models can facilitate the communication between the people involved in the process, they provide a basis for process improvement and they can help perform process management. Processes can be modeled from many different perspectives. Traditional process modeling has followed the process-centric (or activity-centric) perspective, where the focus is on the sequencing of activities (i.e. the control flow), largely ignoring or underspecifying the data required by these tasks. In contrast, the artifact-centric (or data-centric) approach to process modeling focuses on defining the data required by the tasks and the details of the tasks themselves in terms of the changes they make to the data. The BALSA framework defines four dimensions which should be represented in any artifact-centric business process model: business artifacts, lifecycle, services (i.e. tasks) and associations. Using different types of models to represent these dimensions will result in distinct representations, whose differing characteristics (e.g. the degree of formality or understandability) will make them more appropriate for one purpose or another. Considering this, in the first part of this thesis we propose a framework, BAUML, for modeling business processes following an artifact-centric perspective. This framework is based on using a combination of UML and OCL models, and its goal is to have a final representation of the process which is both understandable and formal, to avoid ambiguities and errors. However, once a process model has been defined, it is important to ensure its quality. This will avoid the propagation of errors to the process's implementation. Although there are many different quality criteria, we focus on the semantic correctness of the model, answering questions such as "does it represent reality correctly?" or "are there any errors and contradictions in it?". Therefore, the second part of this thesis is concerned with finding a way to determine the semantic correctness of our BAUML models. We are interested in considering the BAUML model as a whole, including the meaning of the tasks. To do so, we first translate our models into a well-known framework, a DCDS (Data-centric Dynamic System) to which then modelchecking techniques can be applied. However, DCDSs have been defined theoretically and there is no tool that implements them. For this reason, we also created a prototype tool, AuRUS-BAUML, which is able to translate our BAUML models into logic and to reason on their semantic correctness using an existing tool, SVTe. The integration between AuRUS-BAUML and SVTe is transparent to the user. Logically, the thesis also presents the logic translation which is performed by the tool.Els processos de negoci estan directament relacionats amb els objectius de negoci, i per tant és important que aquests processos es duguin a terme de la millor manera possible. Optar per modelar-los pot ajudar a aconseguir-ho, ja que els models proporcionen nombrosos avantatges. Per exemple: faciliten la comunicació entre les parts involucrades en el procés, proporcionen una base a partir del qual millorar-lo, i poden ajudar a gestionar-lo. Els processos es poden modelar des de diferents perspectives. El modelat tradicional de processos s'ha basat molt en la perspectiva anomenada "process-centric" (centrada en processos) o "activity-centric" (centrada en activitats), que posa l'èmfasi en la seqüència d'activitats o tasques que s'han d'executar, ignorant en gran mesura les dades necessàries per dur a terme aquestes tasques. Per altra banda, la perspectiva "artifact-centric" (centrada en artefactes) o "data-centric" es basa en definir les dades que necessiten les tasques i els detalls de les tasques en si, representant els canvis que aquestes fan a les dades. El framework BALSA defineix quatre dimensions que haurien de representar-se en qualsevol model artifact-centric: els artefactes de negoci (business artifacts), els cicles de vida (lifecycles), els serveis (services) i les associacions (associations). Utilitzant diferents tipus de models per representar aquestes dimensions porta a obtenir diverses representacions amb característiques diferents. Aquesta varietat de característiques farà que els models resultants siguin més apropiats per un propòsit o per un altre. Considerant això, en la primera part d'aquesta tesi proposem un framework, BAUML, per modelar processos de negoci seguint una perspectiva artifact-centric. El framework es basa en utilitzar una combinació de models UML i OCL, i el seu objectiu és obtenir una representació final del procés que sigui a la vegada comprensible i formal, per tal d'evitar ambigüitats i errors. Un cop definit el procés, és important assegurar-ne la qualitat. Això evitarà la propagació d'errors a la implementació final del procés. Malgrat que hi ha molts criteris de qualitat diferents, ens centrarem en la correctesa semàntica del model, per respondre a preguntes com ara "representa la realitat correctament?" o "conté errors o contradiccions?". En conseqüència, la segona part d'aquesta tesi se centra en buscar una manera per determinar la correctesa semàntica d'un model BAUML. Ens interessa considerar el model com un tot, incloent el significat de les tasques (és a dir, el detall del que fan). Per aconseguir-ho, primer traduïm les tasques a un framework reconegut, DCDSs (Data-centric Dynamic Systems). Un cop obtingut, s'hi poden aplicar tècniques de model-checking per determinar si compleix certes propietats. Malauradament, els DCDSs s'han definit a nivell teòric i no hi ha cap eina que els implementi. Per aquest motiu, hem creat un prototip d'eina, AuRUS-BAUML, que és capaç de traduir els nostres models BAUML a lògica i aplicar-hi tècniques de raonament per determinar-ne la correctesa semàntica. Per la part de raonament, l'AuRUS-BAUML fa servir una eina existent, l'SVTe. La integració entre l'AuRUS-BAUML i l'SVTe és transparent de cara a l'usuari. Lògicament, la tesi també presenta la traducció a lògica que porta a terme l'eina