How to Describe Workflow Systems to Support

Josefina Guerrero García, Jean Vanderdonckt, Christophe Lemaige, Juan M. González Calleros 1Université catholique de Louvain, Louvain School of Management Place des Doyens, 1 – B-1348 Louvain-la-Neuve (Belgium)

Abstract ticipant to another for action, according to a set of pro- cedural rules” [26]. Workflow Information Systems (WIS) cover the application of information technology This paper addresses a methodology for developing to business problems. Its primary characteristic is the the various user interfaces (UI) of a workflow informa- automation of processes involving combinations of tion system (WIS), which are advocated to automate human activities with information technology applica- business processes, following a model-centric ap- tions. Owing to the fact that the users of a IS interact proach based on the requirements and processes of the with it through its user interfaces (UIs) in the pursuit . The methodology applies to: 1) integrate of organizational goals, flexibility in creating them is human and machines based activities, in particular therefore important. We will explore a systematic way those involving interaction with IT applications and to define UIs for a WIS. The workflow model defines tools, 2) to identify how tasks are structured, who per- what processes and tasks need to be fulfilled and their form them, what their relative order is, how they are possible ordering; hence the workflow model is a offered or assigned, and how tasks are being tracked. ‘framework’ for creating task model, hence the task For this purpose, workflow is recursively decomposed model is suitable for developing UIs. into processes which are in turn decomposed into A short introduction to task and workflow modeling is tasks. Each task gives rise to a task model whose struc- given in section 2, and a modeling language is pro- ture, ordering, and connection with the domain model vided. Section 3 presents the underlying conceptual allows the automated generation of corresponding UIs model of the framework. Section 4 describes our ap- in a transformational approach. proach to develop UIs. Section 5 provides a case study. Finally, in section 6 we conclude and give some notes 1. Introduction on future work. Inside , business processes are performed to ensure that work progress towards accomplishment 2. State of the art of goals. The organization of work, both within and The introduction of Workflow Information Systems in between companies, is becoming more and more com- organizations has emerged as a major advantage to plicated. This is why (computerized) information sys- provide them with a competitive advantage, as a way tems have been developed to support the management to trim cost, to automate process, to reduce time. Im- of processes and their coordination. Today Information plemented properly, workflow applications enable Systems (IS) are part of the organizations with the mis- companies to reengineer and streamline business proc- sion of: 1) improving organizational performance and esses; for this reason, the interest in workflow systems individual quality work life and 2) providing interna- has grown dramatically over the last years. A number tional leadership and education in the successful man- of approaches have been used to model business proc- agement and use of information technology to achieve esses and workflows; those include notations, lan- business objectives [9]. An information system creates guages, and software tools. As notations there are Petri value for the organization as an organizational and Nets [20, 21], Statecharts Diagrams [25, 28], Business management solution to challenges posed by the envi- Process Modeling Notation (BPMN) [13, 27], and ronment. Nevertheless, they have not had the impact UML Activity Diagrams [4]. Currently, several models expected on the improvement to perform the tasks on and design methods support the development of com- the organizations. Workflow is an excellent way to plex workflow-based applications providing notations meet this need. Defined as “the automation of a busi- for describing rich business process including tool sup- ness process, in whole or part, during which docu- port for designing, for instance: The Progression ments, information or tasks are passed from one par- Model [18], YAWL [23], Microsoft Windows Work- flow Foundation (WWF) [5], WebSphere® MQ Work- Hierarchical Task Analysis (HTA)[1], Task Knowl- flow (IBM) [7], WIDE [3], ARIS [17] among others. edge Structure (TKS) [8], GroupWare Task Analysis Due to the large amount of existing workflow prod- (GTA) [24], and ConcurTaskTrees (CTT)[14] which ucts, especially all the commercial software that are all support designers by hierarchically decomposing equipped today with many different capabilities, we tasks, defining objects manipulated and the role re- came to a point where it is very difficult to compare sponsible for performing the task. The vast number of these capabilities on a common scheme. For this pur- task modeling notations results in semantic and syntac- pose, a collection of workflow patterns has been iden- tic differences which are discussed in [11]. tified that provide the basis for an in-depth comparison Task models play an important role in UI design be- of commercially available workflow systems. Control- cause they support the systematic representation of the flow patterns [22] identified useful basic routing con- user activity as opposed to the system activity. structs such as sequence, parallel split, synchroniza- Model-based user interface design is intended to assist tion, exclusive choice. From a data perspective, there is in designing user interfaces with a more formal com- a series of characteristics that occur repeatedly in dif- puter supported methodology; there are solutions to ferent workflow modeling paradigms. Workflow data developing UI that are based in eXtensible Mark-up patterns [15] are aimed at capturing the various ways Language (XML). UsiXML [10, 19] is a XML- in which data is represented and used in workflows. compliant markup language capturing the essence of Workflow resource patterns [16] correspond to the what a UI is or should be independently of physical manner in which tasks are allocated to resources, that characteristics. It has been selected as the User Inter- is any entity that is capable of achieving some work face Description Language (UIDL) to be used in the unit. remainder of this work because of its capabilities of All these approaches for workflow modeling involved extensiveness, availability, central storage of models, in some way the task concept. However none of these and its transformational approach. methods clearly specify the boundaries of a task model and user task which is essential to the development of usable UIs. Examples of task modeling languages are:

processModel

1 1 workflow 0..n processOperator 1

1..n 1..n process sequential parallelSplit simpleMerge

1..n 1 synchronization exclusiveChoice multiChoice 0..n organizationalUnit job 0..n 0..n 1..n 1..n 1..n workItem workList 1..n 0..n 1 2..n

1..n logEntry 0..n taskResource task 1 taskModel 1..n 0..n 1..n 1..n 1 1 0..n 1..n taskRelationship userStereotype meansMaterials immaterial

0..n 1 0..1 machine hardwareM software services decomposition temporal

1 0..n agenda agendaItem 1 0..n

binaryRelationship unaryRelationship

Figure 1 Partial view of the Workflow Model. 3. Conceptual Modeling of Workflow In- 4. How to Generate the User Interfaces formation Systems To develop UIs, we propose a method that is compliant After reviewing the different approaches to model with the Cameleon Reference Framework [2] for de- business process and workflow, we propose a frame- veloping multi-target UIs, which is decomposed in work (Figure 1) that considers the principal compo- four steps (Figure 2): nents to model workflow. The intention is to use this 1) Task and domain modeling (Computing Independ- model as a base to develop UIs. By exploiting task ent Model in MDA): a model is provided for the end model descriptions, different scenarios could be con- user’s task, the domain of activity and, if needed, the ducted. Each scenario represents a particular sequence context of use (user, computing platform, and envi- of actions that can successfully be performed to reach ronment). a goal. Task models do not impose any particular im- 2) Abstract User Interface modeling (Platform Inde- plementation so that user tasks can be better analyzed pendent Model in MDA): this level describes UIs without implementation constraints. This kind of independently of any interaction modality and any analysis is made possible because user tasks are con- implementation. sidered from the point of view of the users need for the 3) Concrete User Interface modeling (Platform Specific application and not how to represent the user activity Model in MDA): this level describes a potential UI with a particular system. after a particular interaction modality has been se- The underlying conceptual model is composed of: lected (e.g., graphical, vocal, multimodal). This step workflow, process, task, and organization models. The is supported by several tools helping designers and workflow model is recursively decomposed into proc- developers to edit, build, or sketch a user interface. esses which are in turn decomposed into tasks. A proc- 4) Final User Interface: this level is reached when the ess model indicates the ordering of processes in time, UI code is produced by interpretation or compiled. space, and resources. Each process gives rise to a proc- As we mention in section 2, UsiXML has been se- ess model structured and ordered with process opera- lected as the UIDL. It describes at a high level of ab- tors. Process operators determine whether the flow of straction the constituting elements of the UI of an ap- work is sequential, parallel split, exclusive choice or plication: widgets, controls, containers, modalities, in- multiple choices, with the corresponding merger op- teraction techniques, etc. UsiXML supports device in- erators, synchronization and simple merge. A process dependence: a UI can be described in a way that re- model uses these operators to order tasks. The work mains autonomous with respect to the devices used in list allows workflow manager to view and manage the the interactions such as mouse, screen, keyboard, voice tasks that are assigned to resources. A task model recognition system, etc. Language provides a means represents a decomposition of tasks into sub-tasks of communication; linguistics—the science of lan- linked with task relationships. We propose an organ- guages—can also be applied to programming lan- izational model that is composed of: organizational guages. By this reason, we introduced the abstract syn- unit, job, resources, and agenda. An organizational unit tax with “enriched” directed graph. That is to say an is a formal group of people working together with one identified, labeled, typed, constrained graph. Finally or more shared goals or objectives. Each task could be we presented the stylistics in a graphical representation supported thanks to a resource model, in which three for the model presented in Figure 1 which relies on types of resources can be found: human resources (i.e. icons. a user stereotype), material resources (e.g., hardware, Model-based user interfaces design often starts with a network, machines), and immaterial resources (e.g., task model that is evolved through an incremental ap- software, operating system). Each resource typically proach to the final UI. For instance, in Figure 2 a task fulfills one or more jobs. The agenda displays the tasks that is no further divided is represented with an Ab- in a tabular format, it enables users to organize and stract Individual Component (AIC). For each AIC a manage their personal work. facet (input, output, control, navigation) and transfor- Transformations are applied in cascade through the mational rules are applied. The next step consists in workflow layers using a mapping model. In order to code generation from a CUI to obtain a FUI. For the support the mapping between the layers, predefined re- complete definition of the method, we refer to [19]. lationships were used: reification, decomposition, As we said before, the aim of this work is to generate isExecutedIn, etc. In this section, only an overview of the UIs of a workflow information system from its this concept is provided, for the complete definition of specifications (provided that they address the relevant the semantics and the syntax, we refer to [6]. aspects) and the different constructs that link the tasks and the users together. 5. Case Study and Tool Support Task & domain Tool support. In order to support the development of UIs from a workflow model to a task model, a work- flow editor has been developed. This editor allows modeling the general workflow defining processes and tasks models, defining organizational units, jobs and resources involved, allocation of tasks to resources, and to manage the flow of tasks. The task model is AUI level based on [12]. Case study. The case study analyzes how people or- ganize the program of small conferences by using a re- view tool. To organize a conference it is necessary to identify the tasks that will be done, the jobs and re- sources which will be involved. These tasks will be as- signed to each job taking into account the role that each of them will play in the workflow. CUI level After the specification of the process to follow, the tasks identified are: find the program committee, pre- pare and distribute the call for paper, install and con- figure conference tool, find keynotes speakers, submit papers, organize submission and reviewing process, assign papers to reviewers, review papers, give feed- back (accept or reject papers), organize discussion to take final decisions, announce results, edit proceed-

FUI level ings, compose program, and attend to the conference and present the paper. Table 1 resumes the principal tasks and the jobs in charge of develop them. Also, the identification of resources that are available for doing the work and where they are working, i.e. the organ- izational unit (Table 2) was specified. Author re- sources are named as A-1, A-2, and A-3 because we do not know who will be interested in submit a paper.

Figure 2 Steps to derive UIs from task models. Table 1. Tasks and jobs identification. Model Visual presentation ID Task Job Process Organizer Reviewer Au- thor 1 Find the program x committee Organiza- 2 Prepare the call x tion for paper 3 Distribute the x call for paper 4 Install confer- x ence tool 5 Configure con- x ference tool 6 Find keynotes x 7 Submit paper x Task 8 Organize sub- x mission 9 Organize review- x Figure 3 Stylistic representation ing process 10 Assign papers to x reviewers 11 Download paper x assigned After, we specify the different jobs and resources in- 12 Review paper x volved in the organization of the conference. It is pos- 13 Ask reviewers x for preferences sible to define some attributes of the job, as the speci- 14 Give feedback x fication, family, grade, and privileges (Figure 5). (accept or reject papers) 15 Organize discus- x sion 16 Take final deci- x sion 17 Announce re- x sults 18 Prepare final x submission 19 Edit proceedings x 20 Compose pro- x gram 21 Attend the con- x ference and pre- sent the paper 22 Edit final pro- x ceeding

Figure 5 Specification of jobs’ attributes Table 2. Resource and organizational unit identification. Also, we specify other attributes for the resource Resource Job Organizational unit (worker): the level of experience, hierarchy level (Fig- Chloé Lambin Organizer UL ure 6), as requirements that the resource needs to ful- Jacques Khelil Organizer UL fill. The number of resources available for each organ- Ellen Martin Organizer UL Angela Buker Organizer UL izational unit can be specified once the resources have Steve Geller Reviewer Reviewer’s university been entered (small dots with a number in Figure 4). Rachel Walsh Reviewer Reviewer’s university Dylan Leitz Reviewer Reviewer’s university A-1 Author Author’s university A-2 Author Author’s university A-3 Author Author’s university

Within the workflow editor, we represent each organ- izational unit, i.e. UL, Reviewer’s university, and Au- thor’s university (Figure 4).

Figure 6 Specification of resource’s attributes

After the identification of tasks, jobs, and resources, tasks are allocated or offered to resources in different ways: direct allocation, delegation, history-based allo- Figure 4 Specification of organizational units cation, among others. This assignation (Table 3) is elaborated after the analysis of the characteristics (qualifications, skills, abilities, experience, and hierar- type. This step allows specifying if the task will be al- chy level) of each resource and considering the re- located or offered to an individual resource or to a quirements of each task. For instance, Install confer- group of resources, and the time that the task is allo- ence tool task was assigned to Ellen Martin because cated. After, we select the resource (worker) that will she is computer engineering. develop the task (Figure 7). As we can observe, task Find the program committee is directly allocated to Table 3. Assigning tasks to resources. Chloé Lambin, who plays the job of organizer. Task Job Resource Pattern In the same way, all the identification of jobs, re- Find the pro- Organizer Chloé Lambin Direct allo- sources, and tasks allocation is specified. gram commit- cation tee Prepare the call Organizer Jacques Khelil Capability for paper based Distribute the Organizer Jacques Khelil Retain famil- call for paper iar Install confer- Organizer Ellen Martin Capability ence tool based Configure con- Organizer Ellen Martin Retain famil- ference tool iar Find keynotes Organizer Chloé Lambin Capability based Submit paper Author A-1, A-2, A-3 Deferred Organize sub- Organizer Jacques Khelil History mission based Organize re- Organizer Chloé Lambin Capability viewing proc- based Figure 7 Selecting the resource. ess Assign papers Organizer Angela Buker Hierarchy to reviewers level based Once workflow components have been identified and Download pa- Reviewer Steve Geller, Direct allo- specified on the workflow editor, we can detail in deep per assigned Rachel Walsh, cation the steps to carry out task using task models. To exe- Dylan Leitz cute the task Submit paper, it is necessary to develop a Review paper Reviewer Steve Geller, Direct allo- series of sub-task in order to accomplish the task, i.e. Rachel Walsh, cation Dylan Leitz the author needs to log in on web page, the system dis- Ask reviewers Organizer Chloé Lambin Retain famil- play the web site where the author fill out his personal for preferences iar data and submit his article, the systems gives a feed Give feedback Reviewer Steve Geller, Capability back so the author knows if there is an error or not (accept or re- Rachel Walsh, based with the file uploaded (Figure 8). ject papers) Dylan Leitz Organize dis- Organizer Chloé Lambin Direct allo- cussion cation Take final de- Organizer Angela Buker Capability cision based Announce re- Organizer Jacques Khelil Distribution sults by allocation single re- source Prepare final Author A-1, A-2, A-3 Deferred submission Edit proceed- Organizer Angela Buker Capability ings based Compose pro- Organizer Chloé Lambin History gram based Attend the con- Author A-1, A-2, A-3 Deferred Figure 8 Representing a task model ference and present the pa- The final workflow model is shown in Figure 9. Now, per Edit final pro- Organizer Angela Buker Capability from task models we derive the UIs of the workflow ceeding based information system using the method proposed in sec- tion 4. It is possible to represent those concepts in the work- flow editor. First, we select the job and the allocation are been developed, if there is a “bottle neck”, to know the status of each task, if the deadline is close, if a task is delegated, etc.

Figure 9 Workflow to organize a conference

To get the various UIs in this case study, a set of trans- formation rules were applied [19]. The intention is to generate the UIs for each interactive task involved in Figure 12 Work list the workflow; considering that if the workflow changes, these changes will be reflected in an auto- 6. Conclusion matic way in each UI. This paper has addressed a methodology for develop-

ing the various user interfaces of a workflow informa- tion system, which are advocated to automate business processes, following a model-centric approach based on the requirements and processes of the organization. So far, the focus has been put mostly on the workflow information systems to support business process. For this purpose, a conceptual modeling approach inte- grates the following concept defined through a meta- model: workflow, process, task, domain, job defini- tion, organizational structure, and resources. These concepts along with their attributes have been inte- grated in UsiXML V1.8, the last version available of Figure 10 User interface example UsiXML today. A transformational approach has been followed to progressively decompose the workflow As we mention on section 3, it is necessary to advertise model into processes which are in turn decomposed to resources about the tasks that are available or allo- into tasks. From each task model, transformational cated. For instance, tasks assigned to Chloé Lambin, rules were applied in order to generate the different who plays the job of organizer, are listed in her agenda UIs involved in the workflow. A workflow editor- (Figure 11). manager tool has been developed to support the method enactment. The major benefit of the above method is that all the design knowledge required to progressively move from a workflow specification to its corresponding UIs is expressed in the model and the mapping rules. As future work, usability guidelines will be applied in the generation of UIs, workflow analysis methods will be taken into account. A case study has been reported and summarized to demon- strate the feasibility of this approach. This method has been so far validated on 4 real-world case studies (e.g., Figure 11 Agenda a hospital dept., a triathlon organization, a cycling event, and personalized order of compression stock- In order to control how the work is flowing, which ings over Internet). More information, including a tasks are in execution or were finished, the workflow video demo of the software can be found at manager has his own work list (Figure 12). The pur- http://www.usixml.org/index.php?mod=pages&id=40. pose of the manager work list is to control how tasks Acknowledgments. We gratefully thank the support from 13. Object Management Group. Business process modeling the SIMILAR network of excellence, supported by the 6th notation specification, final adopted specification Framework Program of the European Commission, under dtc/06-02-02 (2006). contract FP6-IST1-2003-507609 (http://www.similar.cc), the 14. Paternò,F. Model-based design and evaluation of inter- Alban program (www. programalban.org) supported by active applications. Applied Computing, Springer. European Commission, and the CONACYT 1999. (www.conacyt.mx) program supported by the Mexican gov- 15. Russell, N., ter Hofstede, A.H.M., Edmond, D., van der ernment. 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