User experience-based evaluation of open source Workflow systems :

The cases of Bonita, Activiti, jBPM, and IntalioKarim Baïna and Salah Baïna

Alqualsadi research team of Enterprise Architecture, ENSIAS, Université Mohammed V-Souissi, BP 713 Agdal,

R abat, Morocco baina@ensias.ma

Abstract— The task of selecting a workflow system becomes more and more complex and risky. For this reason, organisations require a broad, and a clear vision of which workflow engines are, and will continue to be, suitable for changing requirements. This paper presents a user experience based evaluation model for workflow systems to analyse, compare, and select business process management modelling and enactment systems according to user specific requirements. After the description of the underlying worflow system evaluation model itself, we experiment it to assess criteria satisfaction on four open source workflow systems Bonita, Activiti, jBPM, and Intalio.

Keywords— Business Process Management Systems, Workfolow Management Systems, evaluation criteria, user centric evaluation.

I. INTRODUCTION

Enterprise business models are becoming more and more complex, involving numerous interacting applications within rich business and technical contexts. Thus, enterprise business processes inherit this business models growing complexity. Since those business processes are considered in the enter- prise business core strategy, they need workflow engines that handle suitably the continuously growing business processes management complexity.

With their low capital expenditure (CAPEX), Free and Open Source Software (FOSS) are a very serious opportunity for emergent countries. More than being an IT strategy, FOSS is a real Business strategy with well established business models and organisation. FOSS will enable emergent countries to develop knowledge, through open innovation, brand equity, real local software industry, and to make foreign currency economy. Without FOSS, emergent countries will remain dependent to the same IT software suppliers which represent a concrete risk for their autonomy and sustainable and durable development [1].

We have been observing and studying many interesting FOSS tools that show an increasing opportunity, among others open source enterprise architecture tools [2] and open source worflows systems [3], [4]. We have been working with and observing the evolution of first open source workflow system since 15 years, where neither maturity nor executability were really comfortable.

Few years ago, jBPM and Intalio BPMS became two pioneer examples of open source products gaining more and more attention

and popularity [5]. Perseverance and Innovation of the open source communities arround the world in one hand, involvment and partnership of computer development companies in the other hand made those two examples only the first element of a very valuable list of experiences that lead to very competitive tools and environments.

Nowadays, open source workflow management systems (WfMS)1 are becoming numerous, interesting in terms of functionalities which makes the task of selecting an open source WfMS complex and risky for the enterprise. For this reason, organisations require a broad, and a clear vision of which workflow engines are, and will continue to be, suitable for changing requirements. Selection of such workflow engines is strategic for nowadays organisations.

Our contribution is to present our workflow system evalua- tion model, and to experiment it on four open source workflow system Bonita, Activiti, jBPM, and Intalio. The paper is organised as follows : section II discusses related works, section III presents our workflow engines evaluation model, section IV illustrates the approach through the results of our workflow engines evaluation model experiment, and section V concludes and gives an outlook for this work.

II. RELATED WORKS

Many other works have studied the problem of producing a generic workflow engine evaluation model, but none of them has proposed a rich workflow evaluation model as we propose (35 evaluation sub-criteria). [6] compares workflow engines according to their process definition metamodels through eight criteria : Granularity, Control Flow, Data Flow, Organisa- tional Model, Role Binding, Exception Handling, Transaction Support, and Commitment Support. [7] compares workflow engines according to their organizational meta model, and Process Meta Model richness and expressivity. [8] tackles the comparsion problem from the point of view of the ability of workflow engines to support workflow patterns. [9] bases its evaluation of scientific workflow engines on four criteria :

1 in the remainder of this paper, the terms worflow engine (WFE), worflow management system (WfMS) and business process management systems (BPMS) will be used interchangeably.

Workflow Design, Workflow Scheduling, Fault Tolerance, and Data Movement. [10] focuses its evaluation on a subset of five sub-criteria of [11] software quality criteria : Reliability, Usability, Efficiency, Maintainability, and Portability.

We have ourselves achieved an evaluation experiment in 2007 that has highlited the top 3 WFE at that time : jBPM, OpenWFE & Enhydra Shark among a set of 35 studied open source workflow engines [3], [4] which was profitable for both BPM open source community and BPM research. In fact, our work has influenced and has driven during many years a huge BPM research community (e.g. [12], [13], [14], and their citing papers.) to be more attracted by BPM open source benchmarking within a such large open source community, and to focus later only on the top 3 WFE : jBPM, OpenWFE

& Enhydra Shark with newer visions at that time instead of being lost within a such fertile but not mature production at that time.

III. WORKFLOW ENGINES EVAUATION MODEL

Our workflow engines evaluation model will be presented in three steps : first, section III-A present the chosen criteria for workflow engines evaluation, then section III-B shows how key performance indicators are used to evaluate presented criteria, and finaly section III-C summarizes our approach through the presentation of a workflow engines evaluation metamodel.

A. Workflow engines evaluation criteria model

We have been working many years on an evaluation model that we have built upon 31 criteria and sub-criteria grouped in three axes (1) 12 executability criteria clustered in 3 sub- axes (1.1) API & GUI support, (1.2) Execution Properties, and (1.3) Software Quality based Factors, (2) 10 vision criteria clustered in 2 sub-axes (2.1) Model Richness, and (2.2) Operations & statistics support, and (3) 9 contextual criteria clustered in 3 sub-axes (3.1) Applicative architecture, (3.2) Technical architecture, and (3.3) Licensing and Affiliation [4]. Those criteria and their sub-criteria were built on a bottom-up approach gathering criteria proposed by WARIA (Workflow And Reengineering International Association) [15], or highlighted by workflow research [16], [17], [18], [19], [20], [21], from software quality factors defined by McCall et al. [11], and finally from auxiliary contextual properties on Workflow engines.

Our new evaluation model aims to be more user oriented, either end-user or developer, with a top-down approach. It is built upon 34 new criteria clustered in three sub-classes as shown in (1) 21 executability criteria, (2) 12 vision criteria, and (3) 14 contextual criteria2. These new criteria are sum- marised in figure 1 and described below.

We would like to emphasis that our criteria are a synthesis of most used worklfow system evaluation criteria, and our user experience-based evaluation marks are both resulting from our own experience but also from user experience (developers and end-users) on the blogosphere [22], [23], [5], [24]

2 As you may notice from figure 4, some sub-criteria fit more than one evaluation axis

1) Evaluation Axes: Figure 1 shows evaluation model axes (i.e. criteria classification).

2) Evaluation Criteria:• I1 - Overall Functionality : User appreciation of

the overall completeness of the functionalities of the plat- form.

• I2 - Overall Usability of Tools : User appreciation of the overall usability and reliability of the platform.

• I3 - License : Openness of the license of the tool based on a comparison of various features of licenses of the four tools taking in account conditions of each license.

• I4 - Standard Respect : Overall Appreciation of stan- dards respect .

• I5 - Process Modelling Language (BPMN) : Richeness and completeness of the modelling language and the full- compliance with the BPMN standard.

• I6 - Process Execution Language : Compliance with standards and formats for process execution.

• I7 - Support of Wf-XML : Implements (or not) WF-XML interaction format

• I8 - Support of XPDL : Import and Export functionali- ties in a standard XPDL format.

• I9 - Process Engine (PVM) : Embed a Process Virtual Machine with adequat API.

• I10 - Database, Versionning and Transactions Man- agement : Functionalities and components of the embed- ded database management solution.

• I11 - Dynamic Deployment : Enable Dynamic de- ployment of new versions of processes with automatic upgrade of existing instances.

• I12 - Process Designer for dev : Technical Environment and tools for advanced developers.

• I13 - Integration with Development Frameworks : Facilities to integrate processes with development frame- works, Application Servers and portals.

• I14 - Application Development (API, Debug & Tests) : Development Environment, API and facilities for imple- menting processes.

• I15 - Form Designer : Tools to easily define human forms for web application.

• I16 - Process Design for Business users : High abstrac- tion level tools to define and design processes

• I17 - Process Administration & Monitoring tools : Quality of the provided tools for process instanciation, instance management from administration view.

• I18 - BAM : Embed or indicate tools to handle business activity monitoring.

• I19 - BRE: Embed or indicate engine to execute and manage business rules.

Fig. 1.Workflow Engine Evaluation Criteria Axes

• I21 - WS/Human Task Support: Implements WS/Human Task Standard.

• I22 - Content Manegement Integration: Offers con- nectors to interoperate with most popular content man- agement tools (CRM,ERP,CMS,Reporting, etc.).

• I23 - Connectivity: Offers connectors to integrate process with other components of Enterprise Information Systems.

• I24 - Simulation: Offers tools to simulate execution of processes.

• I25 - Rapid Dev: Offers Environment for agile de- velopment (prototyping, forms generation, application generation).

• I26 - SOA Friendly: Ready to use interface to commu- nicate with an ESB.

• I27 - Restfull: Implements REST protocole for machine to machine interaction.

• I28 - Resource Management (LDAP Friendly): ready to use interface to communicate with an LDAP repository.

• I29 - Maturity: User Centric appreciation of maturity of the environment and its component.

• I30 - Performance: Appreciation of performance and resource usage (cpu/memory).

• I31 - Adoption/Popularity: Number of Downloads and user satisfaction.

• I32 - Release Activity: Frequency of bug correction and release of new versions.

• I33 - Resources and Community: References, Books, Case Studies.

• I34 - Success Stories: Projects that have resulted in substantial achievements with regard to the tool. Rules.

B. Workflow engines evaluation key performance indicators model

We can divide the presented criteria in two categories : those one may evaluate through a mark and those which are contextual and less subject to an effective mark. For example, what should mean a mark affected toLicencing and Affiliation? We consider that contextual criteria have not to be marked while execution properties and vision criteria have to be. Each high level criteria is seen as a hierarchical marked criterion that aggregates the set of all its submarked criterion marks trhough a criterion formula (in the same vain of multidimensional database roll-up aggregation operation). In the following, aggregation formulas of each hierarchical marked criterion given at section III-A will be presented and explained. The criterion mark of a hierarchical marked criterion is computed as the uniform arithmetic average of its sub marked criterion (it has been chossen to affect to all atomic sub marked criterion the same weigth =1).

Fig. 3, shows Evaluation criteria Axis/Criteria aggregation formulas.

C. Workflow engines evaluation metamodel

Now that we have presented the criteria and their evaluation we can present our workflow engines evaluation meta-model which is composed of 6 meta-concepts, as shown in Fig. 2).

Fig. 2. Evaluation criteria metamodel

Fig. 3.Evaluation criteria Axis/Criteria aggregation formulas

• WFEmeta-concept : represents a workflow engine entity with its WFE_ID, and WFE_NAME;

• CRITERION meta-concept : represents an abstract work- flow engine criterion entity with its CRITERION_ID, CRITERION_NAME, CRITERION_DESCRIPTION, and given evaluation CRITERION_COMMENT;

• CONTEXTUAL_CRITERION meta-concept : represents a concrete workflow engine textual criterion entity that describes the evaluation result of WfMS according to a contextual property ;

• HIERARCHICAL_CONTEXTUAL_CRITERION meta-concept : represents a hierarchical concrete workflow engine contextual criterion entity that is composed of many CONTEXTUAL_CRITERION entities ;

• MARKED_CRITERION meta-concept : represents a con- crete workflow engine criterion entity with its given evaluation floating CRITERION_MARK;

HIERARCHICAL_MARKED_CRITERION meta-concept:represents a hierarchical concrete

workflow engine marked criterion entity that iscomposed of many MARKED_CRITERION

entities. This hierarchy aggregates the set of all its SUB_MARKED_CRITERION.CRITERION_MARK through CRITERION_FORMULA (in the same vain of multidimensional database roll-up aggregation operation).

D. Evaluation Axis/Criteria Correspondance:

Fig. 4, shows evaluation axis/criteria correspondance matrix.

IV. WORKFLOW ENGINES EVALUATION MODEL EXPERIMENT

A. Workflow engines evaluation process

The evaluation process attributes for each studied workflow engine its evaluation information (i.e. the set of contextual and marked criteria). The evaluation information is based upon studying their related research papers, marketing white papers, and slides, setting up and testing technically all engines according

to a complete functional case study process. The case study was based on six different processes :

(P1) ISO 9002 preventive, and corrective actions process

(P2) purchase management process

(P3) recruitment process

(P4) expense report reimbursement process

(P5) loan management process

(P6) leave application processEvaluation of a workflow engine is achieved by giving

subjective marks : for each WFE, and CRITERION a floating evaluationMARKis given from0to5(0is the worst mark, and5is the best mark), then aggregated marks and key performance indicators are computed on the basis of the evaluation basic information.

B. Workflow engines subject of evaluation

Without loosing in generality, we present an experiment of our evaluation model on four open source workflow systems : Bonita, Activiti, jBPM, and Intalio.

1. jBPM[25] : under Apache/Eclipse/MIT Licence, jBPM is the first historical reference in the domain of open source BPM and workflow tools, it has been promoted byJBossas the leader of open source business process engines. In the last version, JBoss made huge efforts to integrate a business rules management system to jBPM, these efforts lead jBPM to meet Drools.

jBPM is based on the BPMN 2.0 specification and supports the entire life cycle of the business process (from authoring through execution to monitoring and management). It jBPM offers open-source business process execution and management, including (i) embeddable, lightweight Java process engine, supporting native BPMN 2.0 ex- ecution (ii) BPMN 2.0 process modeling in Eclipse (developers) and the web (business users) (iii) process collaboration, monitoring and management through the Guvnor repository and the web console (iv) human interaction using an independent WS-HT task service; (v) tight, powerful integration with business rules and event processing.

Fig. 4. Evaluation Axis/Criteria correspondance matrix

In order the continue implementing their own phyloso- phy endependently from JBoss directives, initial creators of jBPM made a fork called Activiti based on the forth version of jBPM4.

Fig. 5.experimenting (P5) loan management process on jBPM4 (integrated with

Alfresco) [26]

2. Activiti[27] : under an Apache Licence, Activiti is a light-weight workflow and Business Process Man- agement (BPM) Platform targeted at business people, developers and system admins. Its core is a fast and solid BPMN 2 process engine for Java. It is a full open-source solution and distributed under the Apache license.Activitiruns in any Java application, on a server, on a cluster or in the cloud. It integrates perfectly with Spring, it is extremely lightweight and based on simple concepts.Activitiacknowledges that executable business processes must be applicable as a component in everyday software development. That’s whyActiviti spends a lot of effort in making sure that it can be used very easily in *every* Java environment. This includes the cloud as soon many applications will be written for the cloud.Activiti’s primary purpose and focus is toimplement the general purpose process language BPMN 2.0 but also to support any custom process languages built on top of it.

Fig. 6.experimenting (P4) expense report reimbursement process on Activiti.

3. Bonita[28] : under a GPL forBonitaOpen Solution (BOS) studio & a LGPL for BOS execution engine, Bonitawas initialy developped by Bull, and it has been recently outsourced under the control of an independent company BonitaSoft. Bonita is available under two packages an open source comunity edition and a commercial one.Bonita’s purpose is to offer a simple, intuitive and

graphical solution that support development of ready to use BPMN process based applications.

Fig. 7.experimenting (P4) expense report reimbursement process onBonita.

1. Intalio[29] : under Intalio|BPMS Community & Commercial Edition licences, The last tool in this selection is Intalio, also available under two packages (community and commercial).Intaliocreators prensent the tool as the Modern Way To Build Business Applications. The aim of Intalio is to provide tools and technologies that businesses use to build engaging, agile business applications that include the modern capabilities that users demand, including collaboration, process automa- tion, mobility and cloud enablement. It is clear that commercial strategies of Intalio make it less and less compatible with open source licenses and phylosophy. Involving such a tool in our experiment, helps us to compare full open source solution supported only by community with commercial oriented tools.

Fig. 8.Experimenting ( P2) purchase management process on Intalio.

The study presented in this paper is the result of a detailed and time-consuming analysis of functionalities and features of each one of these tools. Now that comparison criterias have been defined, future work could easily integrate other BPM open source and open source like tools (ProcessMaker, Enhydra Shark, Orchestra, Runa, etc.).

C. Workflow engines evaluation results

The following figures 9 and 10, and table classify graphi- cally, and describe textually the four WfMS in detail.

Our evaluation experiment results informs that generally, priorities taken into account by open source workflow engines software editors, are nowadays : (1) API & GUI support is the most common functionality ; then (2) the model richness, then the execution properties ; then (4) software quality factors ; and finally (5) Operations and statitics.

The interpretation of our results can be made under the three main axes of the analisys Executability, Vision and Context.

Axis I - Executability: after analysing results of the comparison process, the following ranking in the executability axe has been validated (1) Bonita, (2) jBPM, (3) Activiti and finally (4) Intalio. Unsurprisingly, the very high quality of the BonitaStudio designer and it’s high level usability made it at the top of our ranking. At the other extremity of the ranking, Intalio’s choices to not implement some of the most important standards (e.g. XPDL), but also the choice of a very limited connectivity in the community edition(connectors are meant to be non-free and also very expensive) made it attend the last position of this analysis.

Axis II - Vision & Innovation: Results achieved in this axis give the following ranking (1) Bonita, (2) Activiti, (3) jBPM, (4) Intalio. The evaluation marks obtained by the four tools are very similar, what should particularly be noticed is that Activity has a good vision ranking, this statement could make him a good challenger in the next few years. Indeed, despite his low executability mark (in comparison toBonita and Jbpm in Axis I analysis), Activiti vision takes advantage from the orientation of his developers trying to be as standard compliant as possible,Activititakes also advantage from the clear orientation to meet SOA in order to achieve a BPM/SOA convergence solution. At the end of the list, we find Intalio, again. Intalio suffers from his very constraining license and his lake of will to integrate with other components to build a full BPM tool instead of beeing simply a workflow engine.

Axis III - Context: Due to their wide communities, documentation sources and books, but also the numerous forums, blogs dedicated to their issues and features ;Bonita and jBPM seem to be very popular and very well adopted by the open source developpers. Many years of development and improvements made Bonita, jBPM and Intalio admitted as very mature tools. How ever as we stated before, Activiti has all the caracteristics of an outsider that could change the statu quo in the next few years.

CONCLUSION

This paper has presented our workflow systems evaluation model and experiment on four open source workflow engines : Bonita, Activiti, jBPM, and Intalio. Our evaluation experiment has revealed preliminary user-experience based classifications among the top four open source workflow systems.

In summary we believe that, once the research and develop- ment work on the aspects described above has been completed, this approach will result in a comprehensive platform that can substantially reduce (i) WfMS presenting and understanding effort both for editors and customers, and (ii) WfMS selection effort and

therefore foster the widespread adoption of either open source or commercial workflow technology.

Fig. 9. Aggregation Table, and 2D Bull evaluation results examples

Fig. 10. Radar Graph evaluation results examples

REFERENCES

[1] K. Baïna, “Foss as IT & Biz strategy for emergent coutries - Moroccan case study, at Software Freedom Day Casablanca, Morocco,” September, 22

2012. [Online]. Available: http://fr.slideshare.net/kbaina/software- freedomdayfossasitbizstrategy

[2] K. Baïna, “Quels Outils pour l’Architecture d’Entreprise dans le monde du Logiciel Libre ?” May, 7 2010. [Online]. http://fr.slideshare.net/kbaina/enterprise-architecture-and-open-source

[3] K. Baïna, F. Z. Azayite, N. Belakbir, H. Srir, and K. Benali, “Workflow engines comparison model,” inProceedings of the First International Conference on Research Challenges in Information Science (RCIS’07), Ouarzazate, Morocco, C. Rolland, O. Pastor, and J.-L. Cavarero, Eds., April 23-26, 2007, pp. 289–296.

[4] K. Baïna, “WFESelector - A tool for comparing and selecting work- flow engines,” inProceedings of the Ninth International Conference on Enterprise Information Systems (ICEIS’07) (1), Volume DISI, Funchal, Madeira, Portugal,, J. Cardoso, J. Cordeiro, and J. Filipe, Eds., June 12-16, 2007, pp. 330–337.

[5] P. Nie, R. Seppälä, and M. Hafrén, “Open Source Power on BPM - A Comparison of JBoss jBPM and Intalio BPMS, T - 86.5161 Special Course in Information Systems Integration,” 2011, http://jannekorho- nen.fi/project_report_final_BPMS.pdf.

[6] K. Lei and M. Singh, “A comparison of workflow metamodels,” 1997. [Online]. http: // iteseer.ist.psu.edu/lei97comparison.html

[7] M.M. Rosemann and M. zur Muehlen, “Evaluation of Workflow Management Systems - a Meta Model Approach,”Australian Journal of Information Systems, vol. 6, no. 1, pp. 103–116, 1998.

[8] W.M.P. van der Aalst, A.H.M. ter Hofstede, B. Kiepuszewski, and A.P. Barros, “Workflow patterns,”Distrib. Parallel Databases, vol. 14, no. 1, pp. 5–51, 2003.

[9] J. Yu and R. Buyya, “A taxonomy of scientific workflow systems for grid computing.”SIGMOD Record, vol. 34, no. 3, pp. 44–49, 2005.

[10] K. Stoilova and T. Stoilov, “Comparison of workflow software products,” inInternational Conference on Computer Systems and Technologies, CompSysTech’2006, 2006.

[11] J. McCall, P. Richards, and G. Walters, “Factors of software quality,” NTIS, vol. 3, Nov. 1977.

[12] P. Wohed, N. Russell, A. H. M. ter Hofstede, B. Andersson, and W. M. P. van der Aalst, “Open source workflow : A viable direction for bpm ?” in Advanced Information Systems Engineering, 20th International Confer- ence, CAiSE 2008, Montpellier, France, June 16-20, 2008, Proceedings, ser. Lecture Notes in Computer Science, Z. Bellahsene and M. Léonard, Eds., vol. 5074. Springer, 2008, pp. 583–586.

[13] P. Wohed and N. Russell and A.H.M. ter Hofstede and B. Andersson and W.M.P. van d er Aalst, “Patterns-based evaluation of open source BPM systems : The cases of jBPM, OpenWFE, and Enhydra Shark,”Information & Software Technology, vol. 51, no. 8, pp. 1187– 1216, 2009.

[14] P. Wohed, B. Andersson, and P. Johannesson, “Open source workflow systems,” inModern Business Process Automation - YAWL and its Support Environment, A. H. M. ter Hofstede, W. M. P. van der Aalst, M. Adams, and N. Russell, Eds. Springer, 2010, pp. 401–434.

[15] “Waria workflow comparative study,” http://www.waria.com/books/study-2004.htm.

[16] M. Reichert and P. Dadam, “A Framework for Dynamic Changes in Workflow Management Systems,” in8th International Workshop on Database and Expert Systems Applications (DEXA’97), R. Wagner, Ed. Toulouse, France : IEEE Computer Society Press, September 1-2, 1997, pp. 42–48.

[17] A. Bernstein, C. Dellarocas, and M. Klein, “Towards adaptive workflow systems : Cscw-98 workshop report,”SIGGROUP Bull., vol. 20, no. 2, pp. 54–56, 1999.

[18] N. Russell, W.M.P. van der Aalst, A. H. M. ter Hofstede, and D. Edmond, “Workflow resource patterns : Identification, representation and tool support.” inCAiSE, 2005, pp. 216–232.

[19] W. Gaaloul, K. Baïna, and C. Godart, “Towards Mining Structural Workflow Patterns,” in16th International Conference on Database and Expert Systems Applications (DEXA’05), K. V. Andersen, J. K. Debenham, and R. Wagner, Eds., vol. 3588. Copenhagen, Denmark : Springer-Verlag, August 22-26 2005, pp. 24–33.

[20] K. Baïna, K. Benali, and C. Godart, “DISCOBOLE : A service Architecture for Interconnecting Workflow Processes,”Computers in

Industry - Special issue on Collaborative Environments for Concurrent Engineering, Elsevier Science Publisher, pp. 768–777, Dec. 2006.

[21] W. Gaaloul and C. Godart, “Mining workflow recovery from event based logs.” inBusiness Process Management, W. M. P. van der Aalst, B. Benatallah, F. Casati, and F. Curbera, Eds., vol. 3649, 2005, pp. 169–185.

[22] J. A. Maaref, “Evaluation des systèmes de gestion de règles et de flux de travail pour la Chaire de logiciel libre - Finance sociale et solidaire,” Master’s thesis, Université du Québec à Montréal, 2010, maîtrise en informatique.

[23] J. Carhuatocto, “jBPM, Bonita, Intalio, Process- Maker, Activiti. Qué BPM Suite uso ? ,” July 2011, http://holisticsecurity.wordpress.com/2011/07/21/jbpm-bonita-intalio- processmaker-activiti-que-bpm-suite-uso/.

[24] J. Denanot, “Panorama des moteurs BPM/workflow open source,” June 2012, http://www.improve-technologies.com/2012/06/27/panorama-des-moteurs-bpmworkflow-open-source/.

[25] “jBPM,” http://www.jbpm.org.

[26] “Alfresco.” [Online]. Available : http://www.alfresco.com/fr

[27] “Activiti,” http://www.activiti.org.

[28] “Bonita Open Solution,” http://www.bonitasoft.com.

[29] “intalio,” http://www.intalio.com/.