BTRANSFORMER

A Tool for BPMN to CSP+T Transformation

Aleksander González

, Luis E. Mendoza Morales

, Manuel I. Capel

, María A. Pérez

Edumilis Méndez

and Kenyer Domínguez

Processes and Systems Department, Simón Bolívar University, PO Box 89000, Caracas 1080-A, Venezuela

Software Engineering Department, University of Granada, Aynadamar Campus, 18071 Granada, Spain

Keywords: Business Process Modelling Language, Process Calculus, Model Transformation Languages,

Transformation Tool, Formal Software Specification.

Abstract: In any organisation, properties such as scope, structure, deployment, capability, structural consistency and

concurrency, supporting the critical factors for success in Business Process (BP) modelling, need to be

verified. And thus, relevant parts of a BP must be formally specified in an appropriate way. Process Calculi

(PC) such as CSP, ACP, CCS, which constitute a mathematical basis for programming reactive,

communication-bounded systems, can be used to model critical systems and to verify their correctness

properties. PC-based notations can be used to specify business processes (BPs) and reason about their

properties. Without a demanding training, to make use effectively of these languages is beyond the ability of

many business modellers. In order to cope with this drawback, we propose a set of rules to automatically

transform a semi-formal model expressed in terms of Business Process Modelling Notation (BPMN) into a

Communicating Sequential Processes + Time (CSP+T) formal system specification. In this paper, we

present BT

RANSFORMER tool that permits to automatically generate such a formal specification and has been

programmed with the ATLAS Transformation Language (ATL). As result, we obtain a plug-in for Eclipse

platform, which is capable of transforming BPMN models designed with Intalio into a text file with the

equivalent CSP+T formal specification of the business model.

1 INTRODUCTION

Business Processes (BP) models are of use to

represent a set of properties of interest to

organizations, such as scope, capability planning,

process general structure, data dependency, safety

and concurrency (Weske, 2007; Aalst y Hee, 2004).

These properties can be derived from the analysis of

a BP model built using a semi-formal language, such

as BPMN (OMG, 2009) or UML. In order to verify

that a model of a BP satisfies the aforementioned

properties, it is possible to resort to formal

specification languages, capable to represent the

abstract execution of the model, and to verification

tools based on these notations. Communicating

Sequential Processes (CSP) (Hoare, 1985) is a

formal language based on a Process Calculus (PC)

of processes that communicate. Verification tools,

such as FDR (Formal Systems (Europe) Ltd., 2005)

based on CSP, allows modelling concurrent systems

in a structured way, as well as to represent some

model’s behaviours and abstract non-relevant data to

the business interaction level.

The application of model transformations can be

considered an interesting alternative to directly

specifying the initial business process model into a

specific formal language. To use integration

facilities, given by a Model Transformation

Language (MTL), has the main advantage of

permitting the analyst to continue working with a

tool based on a model representation language he is

familiar with, in order to build a semi-formal model

of a BP, whereas any necessary formal specification

of this model can be automatically generated. Thus,

we present here the development of the

RANSFORMER tool, which is based on MTL

ATLAS Transformation Language (ATL) (Jouault et

al., 2008), which allows the user to transform BPMN

models into CSP+T ones, in order to ease the

automatic verification of BPs that are considered

critical to a particular business (Hiles, 2004).

363

González A., E. Mendoza Morales L., I. Capel M., A. Pérez M., Méndez E. and Domínguez K..

BTRANSFORMER - A Tool for BPMN to CSP+T Transformation.

DOI: 10.5220/0003430003630366

In Proceedings of the 13th International Conference on Enterprise Information Systems (ICEIS-2011), pages 363-366

ISBN: 978-989-8425-55-3

 2011 SCITEPRESS (Science and Technology Publications, Lda.)

2 BACKGROUND

2.1 BPMN

BPMN has emerged as an important open standard

graphic notation for modelling and drawing BPs

(OMG, 2009). BPMN specifies a single diagram,

called Business Process Diagram (BPD) (OMG,

2009), which is a flowcharting technique similar to

UML activity diagrams. a BP flow is simply

modelled by the representation of events that occur

to start the BP, activities and tasks carried out, and

the outcome of the BP flow. Business decisions and

flow branching are modelled using gateways.

Furthermore, an activity in the flow can be a sub–

process, which can be graphically shown by another

BPD connected via a hyperlink to a process symbol.

If an activity is not structured into sub–processes, it

is considered a task. Tasks are the atomic parts of a

BP. A pool typically represents an organization or

business entity and a lane, a department or a

business worker within that organization or it may

be other things like functions, applications, and

systems. BPM activity is understood as a successive

refinement process, i.e., once the initial model is

obtained, pools can be further partitioned into lanes.

Both pools and lanes are to represent BP Participants

(OMG, 2009), from which process flows that

perform activities and tasks follow.

2.2 CSP+T

CSP+T (Žic, 1994) is a specification language,

which extends CSP (Roscoe, 2005) to allow the

description of complex event timing sinside single

sequential processes. CSP+T is of much use in the

behavioural specification of concurrent systems that

undergo temporal constrained discrete events.

CSP+T operators related with timing and enabling–

intervals are the following ones: (a) the special

process instantiation event denoted  (star); (b) the

time capture operator (><) associated to the time

stamp function a

= s(e) that allows storing in a

variable a

(marker variable) the time at which event

e (marker event) occurs; and (c) the event–enabling

interval I(T,t

).a, which represents temporal

refinements of the untimed system behaviour and

facilitates the specification and proof of temporal

system properties (Žic, 1994).

2.3 BPMN to CSP+T Transformation

Rules

In a previous work (Mendoza et al., 2011), we have

extended the semantic proposed in (Wong and

Gibbons, 2009) through incorporating CSP+T

operators, which allows the definition of a timed

semantics for a subset of BPMN entities. This opens

up the possibility of using state-of-the-art Model-

Checking (MC) tools to check temporal constraints

between separate event occurrences. Therefore, the

time-capture operator and the event enabling interval

construct of CSP+T are used to give a syntactical

interpretation to tasks’ response times modelling.

Thereby, the temporal constraints required by

business participants in a BP can be formally

specified. Consequently, a more precise and

complete timed semantics of BPMN entities is

obtained than the one given by local and global

BPMN diagrams that represent business

collaboration.

3 BTRANSFORMER TOOL

DEVELOPMENT

We will cover the most relevant aspects of

BTRANSFORMER design.

3.1 Inception Phase

The stakeholders’ needs have been addressed with

the development of BT

RANSFORMER tool; i.e., a tool

that allows an analyst to generate a CSP+T formal

specification from a semi-formal BPMN model.

Special notations with regard to timing constraints

are also considered in the tool. The functional

requirements of BT

RANSFORMER tool can be

expressed as it follows: (FR 1) the tool should

generate a CSP+T specification from a BPMN

diagram, and (FR 2) the tool should allow the

representation of transformation rules of BPMN

constructs as defined in (Mendoza et al., 2011). As

non-functional requirements (i.e., the additional

characteristics of the tool) or (NFR 1), we can

mention: communication and integration facilities

with other tools, and (NFR 2) tool portability. In

Figure 1 is shown the Use Cases (UC) diagram

modelled to cover the previously defined FRs.

As it can be seen in Figure 1, the UC Generate

transformation is highlighted. This is because the

prioritization of UCs decided by BT

RANSFORMER

tool stakeholders UC is considered the most

architecturally significant for the tool can fulfil its

objectives. Thus, the version presented in this work

addresses the full development of this UC, and thus

covers the satisfaction of FR1. In future iterations of

the development the remaining UCs will be

developed.

ICEIS 2011 - 13th International Conference on Enterprise Information Systems

364

uc BTransformer

BTransformer

Configurator

Manage

transformation

rule

Create

transforma tion

rule

Edit

transformation

rule

Delete

transformation

rule

User

Analyst

Generate

transformation

«extend»

Figure 1: UCs diagram for BT

RANSFORMER tool.

3.2 Elaboration Phase

The architectural views suggested at this phase are

the following ones: UC view (Figure 1), Logical

view (Figures 2), Deployment view, Implementation

view and Data view. Due to space limitations, we

will only show the most relevant ones.

We present the Class diagram in Figure 2, which

shows the main abstractions of BT

RANSFORMER

tool’s design; most of them are suggested by the UC

“Generate Transformation” and FR 1. The classes

implemented during construction of the plug-ins of

the transformation tool are defined in Figure 2 and

programmed under Eclipse platform (http://

www.eclipse.org/), as the main development and

implementation environment. Thus, by doing so, we

meet the NFR 2 related to portability of the tool.

The class BPMN2CSPTAction represents the

actions in the menu that allows accessing the

functionality of the tool from Eclipse environment.

Class

ApplyTransformationAction makes use of

the services of the environment and is based on the

values of one or more classes of

Configuration. In

the class Latex, a format is given to the CSP+T

syntactical process terms that result from the

transformation and temporal annotations are

included. The class

ReaderWriter allows managing

the persistence through the storage of the generated

instructions in a file.

The integration of the ATL component in the

Eclipse platform is achieved with the editor Intalio

(http://www.intalio.com/). Figure 3 displays the

components diagram that constitutes the architecture

of Eclipse (http://www.eclipse.org/) platform into

which the development of the plug-in for

RANSFORMER is based.

class BTransformer Class Diagram

BPMN2CSPTAction

+ generateCSPT() : void

+ run(IAction) : void

ApplyTransformationAction

- ObjectiveModel: IReferenceModel

- pathObjectiveModel: List <String>

- pathSourceModel: List <String>

- SourceModel: List <IReferenceModel>

+ cleanFiles(IWorkspace) : void

+ generateTransformation(IReferenceModel) : void

+ transform(IAction) : void

Configuration

- extensionFiles: List

- lib: List

- name: String

- urlObjetive: String

- urlSource: String

Latex

+ Format(Instructions) : String

+ process2Latex(File, File) : void

- processInstrucctions(File) : void

Ti me E v a l ua to r

+ evaluateTime(Instructions) : float

ReaderWriter

+ getContents(File) : String

+ writeContents(String, File) : File

apply

uses

1..*

T a ke t h e se rv i ce s o f

1..*

get the contents of

1 1..*

get time of

Figure 2: Class diagram of BT

RANSFORMER tool.

Figure 3: BT

RANSFORMER tool components.

The feasibility of the project was increased due

to the decision made to use Eclipse platform for the

development of BT

RANSFORMER. Since processing

services of the BPMN editor are always available, it

is not necessary to perform the processing of the

BPMN model at once. Through the action provided

by the Eclipse platform that invokes the plug-in

UITransformationPlugin (see Figure 3), the access

to the functionality of the tool BT

RANSFORMER is

implemented. The transformation process is

facilitated by the plug-in Intalio, which controls the

entire BPMN modelling process of the source

model, and to which the processing rules defined in

the plug-in

TransformationPlugin are applied to.

In its part, the plug-in

UtilsPlugin handles BPMN

modelling entities reading into the source model and

writing CSP+T processes to the object model. All

plug-ins are based on the platform, however Figure 3

BTRANSFORMER - A Tool for BPMN to CSP+T Transformation

365

includes, in addition to the plug-ins developed, these

that allow the implementation of its interface.

3.3 Construction Phase

All the components and the proposed UC are

implemented in this phase. In addition, test cases are

applied to each use case. The main deliverable of

these phases is the first version of BT

RANSFORMER

tool, including the source code of all implemented

classes. Figure 4 shows the screenshot that

corresponds to the invocation of BT

RANSFORMER

tool according to the sub-option Bpmn2CspT, which

activates the plug-in

UITransformationPlugin of

Transformations option. This option can be found in

the context menu (right button of the mouse) on the

XML file of the BPMN diagram generated by

Intalio.

Figure 4: Screenshot of BT

RANSFORMER tool invocation.

3.4 Transition Phase

The current installation of the tool represents

RANSFORMER’s implementation on the

Information Systems Research Lab department

server at Simón Bolívar University, Venezuela, i.e.,

its final certification/pre-production environment.

4 CONCLUSIONS

This paper introduced the development of

RANSFORMER tool that allows executing a

transformation from a BPMN model into a set of

CSP+T process terms. Thus, with our tool a BP

analyst is provided with a formal specification of a

diagram on which a set of properties are

automatically checked. Among the advantages of

using this tool, the following ones can be

mentioned, (1) it facilitates the generation of

specifications in CSP+T from a BPMN model in an

automatic way, and (2) does not require the use of

external elements to the BPMN standard, in order to

specify time management aspects. As future work in

the short term we plan to extend BT

RANSFORMER

and obtain the integration with FDR2. In the long

term our aim is to extend the application of the tool

to other BP modelling languages and some other

PC-based formal specification notations.

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