A Tool for Supporting Object-Aware Processes [original]

A Tool for Supporting Object-Aware Processes

Carolina Ming Chiao, Vera K¨

unzle, Kevin Andrews, Manfred Reichert

Institute of Databases and Information Systems

University of Ulm, Germany

Email: {carolina.chiao, vera.kuenzle, kevin.andrews, manfred.reichert}@uni-ulm.de

Abstract—Although the popularity of activity-centric pro-

cess management systems (PrMS) has increased during the

last decade, there still exist business processes that cannot be

adequately supported by these PrMS. A common characteristic

of these processes, which is neglected by current activity-centric

PrMS, is their need for object-awareness; i.e., the explicit pro-

cessing of business data and business objects respectively. In the

PHILharmonicFlows project, characteristic properties of object-

aware processes were identified and an advanced framework for

their proper support was designed. In this paper, we present a

proof-of-concept prototype implementing some of the fundamen-

tal concepts of the PHILharmonicFlows framework. Overall, this

initiative will result in a new generation of process management

technology.

I. INTRODUCTION

The increasing economic pressure obliges enterprises to

adopt process management systems (PrMS) with the aim

to properly manage and automate their business processes.

Traditional PrMS are activity-centric [13]; i.e., the business

processes to be supported are defined in terms of “black-box”

activities as well as the control flow elements expressing the

orders and constraints for executing these activities. However,

activity-centric PrMS treat business objects only as second-

class citizens [2], [5], which are usually stored in external

databases; i.e., outside the control of the activity-centric PrMS.

Moreover, the strict separation of concerns realized by tra-

ditional PrMS does not allow providing an integrated view

to the end-user; i.e., business data, business functions and

business processes are managed by different kinds of systems,

making it impossible for users to access required context

information during process execution [2]. Instead, respective

information can only be accessed when invoking external

application systems implementing the activities.

Despite their widespread popularity, there still exist numer-

ous processes that cannot be properly supported by traditional

PrMS. These processes can be characterized as knowledge-

intensive, relying on user decisions being characterized as

semi-structured or unstructured [14]. Hence, they cannot be

“straight-jacketed” into a set of activities [2]. Recent works

[1]–[3], [5], [10]–[12], [15] confirmed that the limitations of

existing activity-centric PrMS can be traced back to the lacking

integration of processes, data, and users.

In the PHILharmonicFlows1project, characteristic pro-

cesses from a variety of domains were analyzed [4], [6], [9].

In the respective studies, we contrasted different application

scenarios with a set of properties, which were extracted from a

systematic literature study. This way, we showed that the prop-

erties are related to each other and their support is required

1Process, Humans and Information Linkage for harmonic Business Flows

http://www.uni-ulm.de/en/in/dbis/research/projects/philharmonic-flows.html

by a variety of processes from different application domains;

i.e., generalization is possible. Common to all these processes

is their need for object-awareness; i.e., business processes

and business objects must not be treated independently from

each other. In general, object-aware processes present three

major characteristics. First, they can be based on two levels

of granularity. On one hand, the behavior of individual object

instances needs to be considered during process execution; on

the other, the interactions among different object instances

must be taken into account as well. Second, the execution

of these processes is data-driven; i.e., the progress of a

process depends on available object instances and the values

of their attributes. Third, flexible activity execution is crucial.

In particular, activities do not have to coincide with particular

process steps. In this paper, we officially present for the first

time a proof-of-concept prototype implementing the concepts

of the PHILharmonicFlows framework. This prototype com-

prises both a build-time and a run-time environment, which

enables the modeling, execution and monitoring of object-

aware processes.

Section II summarizes the basic concepts of the PHIL-

harmonicFlows framework, whereas Section III presents the

architecture and features of the implemented proof-of-concept

prototype. Section IV concludes the paper.

II. PHILHARMONICFLOWS FRAMEWORK

The PHILharmonicFlows framework enforces a well-

defined modeling methodology governing the object-centric

specification of business processes based on a well-defined

formal semantics [7], [9]. More precisely, the framework

enforces the definition of processes at two levels of granularity.

While object behavior is defined at micro process level, object

interactions are captured at macro process level. Due to the

lack of space, we only give an overview of PHILharmon-

icFlows in this paper. For more details, please refer to [7],

[9]. For related work, please refer to [8].

As a fundamental prerequisite, first of all, object types and

their relations need to be captured in a data model (cf. Fig. 1a).

Then, for each object type, a corresponding micro process type

has to be specified (cf. Fig. 1b). The latter defines the behavior

of related object instances, and consists of a set of micro

steps as well as the transitions between them. In turn, each

micro step is associated with an object type attribute. Further,

micro steps are grouped in object states. At run-time, for

each object instance a corresponding micro process instance

is created. A micro process instance being in a particular

state may only proceed if specific values are assigned to the

object instance attributes associated with this state; i.e., a data-

driven process execution is provided. In turn, optional data

access is enabled asynchronously to micro process execution

RUN-TIME

BUILD-TIME

Data Model

Micro Process

Macro Process

Object Type States

Micro Steps

Micro

Transitions

Macro Steps

Macro

Transitions

Relations

Attributes

Coordination

Overview

Tables Worklists

Forms

Authorization

Process Context

Aggregation

Transverse

Permissions

User Assignment

Black-box

activities e

Fig. 1. The PHILharmonicFlows framework

based on the permissions granted for reading or writing object

attributes. In particular, access rights for an object instance

may also depend on the progress of the corresponding micro

process instance. For this purpose, the framework maintains

an authorization table assigning data permissions to user roles

which may additionally depend on the respective state of the

micro process type (cf. Fig. 1c). Based on this authorization

table, PHILharmonicFlows automatically generates user forms

at run-time. Which input fields are displayed to the respective

user depends on the permissions he has in the currently

activated state (cf. Fig. 1d). Additionally, PHILharmonicFlows

allows for the integration of black-box activities, enabling the

realization of more complex business functions for which a

specific implementation is required (cf. Fig. 1e).

Taking the relations between the object instances of the

overall data structure into account, the corresponding micro

process instances form a complex process structure; i.e., their

execution needs to be coordinated in compliance with the given

data structure. In PHILharmonicFlows, this is accomplished by

means of macro processes. A macro process type consists of

macro steps linked by macro transitions (cf. Fig. 1f). Opposed

to micro steps, which refer to single attributes of a particular

object type, a macro step refers to a particular state of an object

type. In addition, for each macro transition, a coordination

component must be specified (cf. Fig. 1g). The latter hides

the complexity of large process structures from modelers as

well as end-users. More precisely, a coordination component

coordinates the interactions among the object instances of the

same type as well as different types. Opposed to existing

approaches, the semantic relations between the object instances

and their cardinalities are taken into account as well.

III. PROOF-OF-CONCEPT PROTOTYPE

This section describes the basic features of the PHILhar-

monicFlows tool we implemented. Besides demonstrating the

practical feasibility of the PHILharmonicFlows framework, the

following requirements were considered when developing this

proof-of-concept prototype:

•Use of visual models: The tool shall allow for the

graphical definition of data models, micro process

types, macro process types, and authorization tables.

•Enabling correctness-by-construction: The tool

shall enable extensive correctness checks, including

.NET Framework

MS SQL Server 2008

yFiles

ASP.NET

WPF

XAML

Build-time Environment

Graphical Modeling

Correctness Rules

Run-time Environment

Operational Semantics

Instance DataType Data Deployment

PHILharmonicFlows

Schema

generated

Application Schema

defines /

loads

reads /

writes

reads

generates User Interfaces

LinqLinq

Fig. 2. Architecture of the PHILHarmonicFlows tool and technologies used

(from [9])

a proper visualization of modeling errors.

•Persistent model storage: All model artifacts created

(e.g., object and process types) as well as run-time

data (i.e., object and process instances) shall be stored

persistently.

•Automated generation of user interface compo-

nents: The tool shall automatically generate end-user

components (e.g., overview tables, user forms, and

worklists) based on the defined models.

•Correct process enactment: The tool shall allow for

correct execution of object-aware processes. For this

purpose, it must implement the operational semantics

defined for micro and macro processes by the PHIL-

harmonicFlows framework.

A. Architecture

The PHILharmonicFlows tool comprises both a build- and

a run-time environment (cf. Fig. 2).

The build-time environment provides graphical user inter-

faces for defining data models, micro and macro process types,

and user authorizations. In this context, a “correctness-by-

construction” principle is applied, and correctness checks for

the various models are provided. For example, it is not possible

to have two micro step types referring to the same attribute type

at the same state type. Further, all created models are stored

in the build-time database.

Before creating and enacting instances of an object-aware

process, the respective models need to be deployed to the run-

time environment. For the run-time database, a corresponding

application schema is automatically generated based on the

pre-specified models. This run-time database is then used to

store instance data persistently. Opposed to the build-time

aBuild-time architecture

bRun-time architecture

Fig. 3. Run-time and build-time architectures (from [9])

environment, which corresponds to a single-user system, the

run-time environment is implemented as web application that

may be accessed concurrently by various users. In particular,

the run-time environment provides generic support for au-

tomatically generating user interface components (e.g., user

forms and worklists) taking the defined data and process

models as input. Furthermore, the run-time environment im-

plements the logic required to correctly execute micro and

macro process instances; i.e., it fully supports the operational

semantics described by the PHILharmonicFlows framework

[9].

The main components of the build-time environment are

as follows (cf. Fig. 3a):

•The build-time DB manager controls the database con-

nection and provides methods for inserting, deleting,

and changing database entries.

•The permission manager checks permissions and re-

sponsibilities, e.g., which attributes may be accessed

by a particular user.

•The consistency manager ensures the “correctness-by-

construction” principle.

•The view manager updates the view of the workspace

according to which dimension (i.e., data structure,

process structure, or user integration) the user selects

on the sidebar (cf. 4).

•The project manager opens, saves, and closes model-

ing projects.

The implemented run-time environment comprises the fol-

lowing components (cf. Fig. 3b):

•The run-time DB manager communicates with the

database of the run-time environment and manages

instance data; i.e., read and write access is provided.

•The build-time DB manager communicates with the

database of the build-time environment and manages

model data.

•The process manager allows creating and enacting

micro as well as macro process instances.

•The form manager automatically generates user forms

based on the various build- and run-time artifacts.

•The permission manager allows for the integration of

user roles; i.e., depending on the currently activated

states of the micro process instances, it controls which

users may access which data at a certain point in time.

•The activity manager controls the functions (e.g., alter

data or handle errors) that may be applied to object

instances.

•The run-time manager is responsible for creating

object instances and assigning attribute values to them.

•The model manager maintains all models for which

there are running instances.

B. Used Technologies

The tool is implemented based on .NET Framework (i.e.,

C#) and Visual Studio. In this context, the graphical frame-

work Windows Presentation Foundation (WPF) was applied

in conjunction with yFiles framework in order to develop the

user interface of the various modeling components. The latter

are based on the usability concepts presented in [16]. The

user interface provides extensive features for creating graphical

models. In addition, user interface components are defined in

a declarative way using the Extensive Application Markup

Language (XAML). In particular, XAML allows separating

design from behavior, which enables the re-use of components;

i.e., overall development time can be reduced significantly.

The run-time environment, in turn, is based on ASP.NET and

MS SQL Server 2008 is the database management system.

To establish the database connections, we use the Language-

Integrated Query (Linq) (cf. Fig. 2).

C. End-User View

The build-time environment of the PHILharmonicFlows

prototype is split into three main components: a menu, a

sidebar, and a workspace (cf. Fig. 4). The sidebar applies

the accordion navigation pattern and permits the user to

select and access areas representing the different modeling

dimensions of a particular object-aware process (i.e., data

structure, process structure, and user integration). In addition,

each area comprises sub-areas. When selecting an area, it

becomes expanded and highlighted. The screen depicted in

Fig. 4 represents the data structure dimension, where the

user defines the data model with its object types and their

relations. In particular, a data model serves as compass for the

corresponding process structures; i.e., by using the data model

as compass, the user may directly indicate in the data model,

for which object type he wants to define a micro process type

(cf. Fig. 5). When modeling a macro process type, in turn, both

data model and micro process type may be used as structure

compasses.

In the run-time environment, the user may choose among

three different views: data,task, and monitoring. The data-

oriented view comprises a panel for selecting the desired

object type on the left and an overview table listing the object

instances (the respective user may access) on the right (cf.

Fig. 6). Based on the data-oriented view, users may search for

object types, filter object instances, create new object instances,

sidebar

workspace

selected

object type

modeling

components

table listing the

attribute types of the

selected object type

Fig. 4. Build-time user interface - Data structure (from [9])

information box

error box

modeling

components

micro process type of the

selected object type

structure compass

selected object

type

Fig. 5. Build-time user interface - Micro process modeling (from [9])

Fig. 6. Data-oriented user view (from [9])

and execute optional as well as mandatory activities on object

instances.

The process-oriented view (i.e., task view) presents a

matrix representing micro process types and corresponding

states as rows, and tasks as columns. In particular, each column

indicate a particular user task; i.e., the user can whether input

data to corresponding attributes, monitor the instances under

his responsibility, or handle instance errors. The user may

select one of the cells of this matrix and accomplish the corre-

sponding task; i.e., the overview table can be considered as a

worklist. In the monitoring view, in turn, users may visualize

the macro process instances as well as related object instances.

In this context, activities for handling macro process instances

(and micro process instances respectively) are provided; e.g.,

for dissolving deadlocks.

IV. CONCLUSION

In this paper, we presented a proof-of-concept tool we

developed in order to validate the technical feasibility of the

PHILharmonicFlows framework. This tool supports the mod-

eling, execution, and monitoring of object-aware processes.

For this purpose, it provides a build-time as well as a run-

time environment. The build-time environment is divided into

three dimensions: data structure, process structure, and user

authorization. In turn, the run-time environment provides three

user views: data-oriented view, process-oriented view, and

monitoring view.

As future work, we will extend the framework and its

implementation by addressing other issues related to object-

aware process management; e.g., historization, traceability,

process variability, and process flexibility (including ad-hoc

changes and schema evolution of object aware processes).

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