1. 2/28/2013
2
Business Process Methodology CHAPTERS’ OBJECTIVES
Chapter 3
Business Process Modeling Foundation • the foundation of business process modeling by
investigating:
▫ abstraction concepts, and
▫ introducing the main sub-domains of business
Prepared by:
Rao Majid Shamshad process modeling, namely:
University of Education, Lahore  modeling functions,
email: majidrao111@yahoo.com  processes,
http:// www.bpm-ue.blogspot.com
 data,
 organization,
 and operation.
3 4
Business processes activities MANUAL ACTIVITIES
• Business processes consist of activities whose • Manual activities are not supported by information
coordinated execution realizes some business systems. An example of a manual activity is sending
goal. These activities can be: a parcel to a business partner.
▫ System activities,
▫ user interaction activities,
▫ manual activities.
1

2. 2/28/2013
5 6
User interaction activities MANUAL + USER INTERACTION ACTIVITIES
• These are activities that knowledge workers • Some activities that are conducted during the
perform, using information systems. enactment of a business process are of manual
• Humans use IS to perform these activities, nature, but state changes are entered in a
application with appropriate user interfaces business process management system by means
need to be in place to allow effective work. These of user interaction activities.
applications need to be connected to back-end • e.g. delivery of a parcel can be monitored by an
application systems that store the entered data IS. Typically, the actual delivery of a parcel is
and make it available for future use. acknowledged by the recipient with her
signature.
7 8
SYSTEM ACTIVITIES
• System activities do not involve a human user;
they are executed by information systems.
▫ An example of a system activity is retrieving stock
information from a stock broker application or
checking the balance of a bank account. It is
assumed that the actual parameters required for
the invocation are available.
• If a human user provides this information, then
it is a user interaction activity. Both types of
activities require access to the respective
software systems.
2

3. 2/28/2013
9 10
WORKFLOW TECHNOLOGY “IS-A” RELATIONSHIP
• Certain parts of a business process can be • is-a or is_a or is a (subsumption) is a
enacted by workflow technology. relationship where one class D is a subclass of
• A workflow management system can make sure another class B (and so B is a superclass of D).
that the activities of a business process are • In other words, "D is a B" (B subsumes D, or D
is-subsumed-by B) usually means that concept D
performed in the order specified, and that the is a specialization of concept B, and concept B is
information systems are invoked to realize the a generalization of concept D. For instance, a
business functionality. "fruit" is a generalization of "apple", "orange",
• No “is-a” relationship. "mango" and many others. One can say that an
apple is a fruit.
11 12
3.2 ABSTRACTION CONCEPTS 3.2.1 HORIZONTAL ABSTRACTION
• To capture the complexity in business process • Along the lines of the levels of abstraction
management, different abstraction concepts are identified by the Object Management Group, the
introduced. meta-model level, the model level, and the
• A traditional abstraction concept in computer instance level play important roles in the design
science is the separation of modeling levels, and analysis of complex systems in general and
from instance level to model level to meta-model software systems in particular.
level, denoted by horizontal abstraction. • It is instructive to explain these levels in a
bottom-up order, starting with the instance
level.
3

4. 2/28/2013
13 14
INSTANCE AND MODEL LEVEL • For instance, a set of similar business process
instances are classified and represented by a
• The instance level reflects the concrete entities business process model. In object modeling, a
that are involved in business processes. set of similar entities is represented by a class,
Executed activities, concrete data values, and and in data modeling using the Entity
resources and persons are represented at the Relationship approach, a set of similar entities is
instance level. represented by an entity type, and similar
• To organize the complexity of business process relationships between entity types are
scenarios, a set of similar entities at the instance represented by a relationship type.
level are identified and classified at the model
level.
15 16
MODEL AND META-MODEL
• Models are expressed in meta-models that are
associated with notations, often of a graphical
nature.
• In data modeling, the Entity Relationship meta-
model defines entity types, relationship types,
and connections between them. Typical
graphical notations of the Entity Relationship
meta-model are rectangles for entity types and
diamonds for relationship types, connected by
lines.
4

5. 2/28/2013
17 18
3.2.2 VERTICAL ABSTRACTION
• Vertical abstraction in business process
modeling is that where distinct modeling sub-
domains are identified. As depicted, process
modeling is at the centre of the modeling effort,
because it also integrates the modeling efforts
that are conducted in the other sub-domains.
19 20
3.3 FROM BUSINESS FUNCTIONS TO
SUB-DOMAINS
BUSINESS PROCESSES
• Function modelling, data modelling, • Value chains provide a high-level organization of
organization modelling, and modelling of the the functions that an enterprise performs. To
operational information technology landscape provide a more detailed view, these top-level
are required to provide a complete picture of a business functions are broken down to functions
business process. While these subdomains are of smaller granularity and, ultimately, to
the most important ones, additional sub- activities of operational business processes.
domains can be defined if they are relevant. • Functional decomposition is the technique of
choice.
5

6. 2/28/2013
21 22
REPRESENTATION OF MODEL
• business functions are represented by
rectangles, while functions of the finest
granularity are represented by rectangles with
rounded corners.
• Functions at the leaf level of the functional
decomposition are also called activities.
23 24
• The sample business process starts with
analyzing the order, and then conducting either
a simple check or an advanced check depending
on the decision made during process execution.
• Events play a crucial role when
interrelationships between business processes
are expressed.
6

7. 2/28/2013
25 26
DEFINITION 3.1
• A functional decomposition of coarse-grained
business functions to fine-granular activities
defines the functional perspective of a business
process
27 28
Granularity
• The terms granularity, coarse, and fine are
• Granularity is the extent to which a system is broken
relative, used when comparing systems or
down into small parts, either the system itself or its
descriptions of systems. An example of
description or observation. It is the "extent to which a
larger entity is subdivided. For example, a yard broken
increasingly fine granularity: a list of nations in
into inches has finer granularity than a yard broken into the United Nations, a list of all states/provinces
feet." in those nations, a list of all counties in those
• Coarse-grained systems consist of fewer, larger states, etc.
components than fine-grained systems; a coarse- • The terms fine and coarse are used consistently
grained description of a system regards large across fields, but the term granularity itself is
subcomponents while a fine-grained description not. For example, in investing, more granularity
regards smaller components of which the larger ones are refers to more positions of smaller size, while
composed. photographic film that is more granular has
fewer and larger chemical "grains".
7

8. 2/28/2013
29 30
3.4 ACTIVITY MODELS AND ACTIVITY INSTANCES • activity models can be expressed in
different forms, for instance, by plain text
• Business functions provide a high-level, coarse- or by some formal specification or
grained representation of the work conducted by
references to software components that
enterprises. Activities can be found in the leaves
of the functional decomposition. implement them.
• An activity model describes a set of similar • Activity instances represent the actual
activity instances, analogously to a process work conducted during business
model describing a set of process instances with processes, the actual units of work.
the same structure. While process models are
typically expressed in graph-like notations
31 32
8

9. 2/28/2013
33 34
STATE OF TRANSITION 3.5 PROCESS MODELS AND PROCESS INSTANCES
35 36
3.5.1 PROCESS MODELS • Edge: Directed edges are used to express the
relationships between nodes in a process model.
• Any modelling effort starts with identifying the main • Node: A node in a process model can represent
concepts that need to be represented. In
metamodelling, the concepts to be represented are an activity model, an event model, or a gateway
models. model.
• Process Model : A process model represents a
blue print for a set of process instances with a • Activity Models: Activity models describe
similar structure. Process models have a two-level units of work conducted in a business process.
hierarchy, so that each process model consists of a Each activity model can appear at most once in a
set of activity models. Nesting of process models
within process models is not represented, because it process model. No activity model can appear in
would introduce complexity that is not required. multiple process models.
Each process model consists of nodes and directed
edges.
9

10. 2/28/2013
37 38
• Event models: Event models capture the
occurrence of states relevant for a business
process. Process instances start and end with
events, so process models start and end with
event models.
• Gateway Models: Gateways are used to
express control flow constructs, including
sequences, as well as split and join nodes.
39 40
• The next step in modelling concerns the • Each node is associated with at least one
identification and formalization of the
edge. The different types of nodes are
relationships between these concepts. Figure
3.14 provides a representation of the concepts
represented by the generalization relation.
and their relationships by a structure diagram, Activity models reflect the work units to be
defining a process meta-model. performed, event models represent the
• Each process model consists of nodes and edges. occurrence of states relevant for the
The nodes represent activity models, event business process, and gateway models
models and gateway models, while the edges represent execution constraints of
represent control flow between nodes. Each edge activities, such as split and join nodes.
is associated with exactly two nodes, relating
them in a particular order.
10

11. 2/28/2013
41 42
While the association between nodes and • Figure 3.15 shows a process model based on the
edges are defined at the node level, the process meta-model introduced. The notation
cardinality of the association between special used to express this process model is taken from
types of nodes (activity models, event models, the Business Process Modeling Notation:
and gateway models) differs. Each activity • Event model nodes are represented by circles;
model has exactly one incoming and one the final event model is represented by a bold
outgoing edge. circle.
• Activity models are represented by rectangles
with rounded edges.
• Gateway models are represented by diamonds.
• Edges are represented by directed edges between
nodes.
43 44
3.5.2 PROCESS INSTANCES • A process instance consists of a number of
activity instances as well as event and gateway
instances. The ordering relationships of activity
• Process models define restrictions on process
instances in a process instance is defined by the
instances that belong to the process model. relationships of the activity models in the
Therefore, it is essential to properly define not process model.
only process models but also process instances. • For instance, if a process model defines an
Modelling process instances is not an easy task, execution ordering constraint between activity
because of their intangible nature. A process models A and B, then for each particular process
instance is started, and it lives for a limited time instance, the activity instance that belongs to
period before it ceases to exist, similarly to activity model A must have terminated before
activity instances. the activity instance for B can be started.
11

12. 2/28/2013
45 46
• Each process instance is associated with exactly • In the case of loops, an activity model is
one process model, and each process model is associated with multiple activity instances. An
associated with an arbitrary number of process activity model that lies on a branch that is not
instances. Each process instance is composed of taken during a particular process instance is not
an arbitrary number of activity instances. Each associated with any activity instance, explaining
activity instance is associated with exactly one the cardinality of the association * that allows
activity model. The same holds for events and zero occurrences of the association, i.e., there
gateways. might be activity models in a process model for
• Note that each activity model is associated with which no activity instances are required for a
an arbitrary number of activity instances. particular process instance.
47 48
3.6 PROCESS INTERACTIONS
• enterprises cooperate with each other, it is
essential to consider the interaction between
enterprises.
• Since all activities that an enterprise conducts
are part of some business process, the
interaction between enterprises can be described
by the interaction of business processes of these
enterprises.
12

13. 2/28/2013
49 50
These interactions typically occur in a peer-to-
peer style, following an agreed-upon process
choreography. EVENT DIAGRAM
51 52
3.7 MODELLING PROCESS DATA 3.7.1 MODELLING DATA
• Data modelling is at the core of database design.
• Business processes operate on data. Explicitly The Entity Relationship approach is used to
representing data, data types, and data classify and organize data in a given application
domain.
dependencies between activities of a business • In a modelling effort, the most important
process puts a business process management entities are identified and classified. Entities are
identifiable things or concepts in the real world
system in a position to control the transfer of that are important to the modelling goal. In the
relevant data as generated and processed during sample scenario, orders, customers, and
products are among the entities of the real world
processes enactment. that need to be represented in the data model.
13

14. 2/28/2013
53 54
• Entities are classified as entity types if they have • The entities classified in an entity type need to
the same or similar properties. Therefore, orders have similar, but not identical structure, because
are classified by an entity type called Orders. attributes can be optional. If the application
Since each order has an order number, a date, a domain allows, for instance, for an order to have
quantity, and an amount, all order entities can or not to have a discount, then the amount
be represented by this entity type. Properties of attribute is optional. This means that two orders
entities are represented by attributes of the are classified in entity type order even if one has
respective entity types. a discount attribute while another does not.
55 56
REPRESENTATION OF ER MODEL 3.7.2 WORKFLOW DATA PATTERNS
• Entity types in the Entity Relationship meta- • To organize data-related issues in business
model need to be represented in a notation by a process management, workflow data patterns
particular symbol. While there are variants of have been introduced. Workflow data patterns
Entity Relationship notations, entity types are formulate characteristics on how to handle data
often represented by rectangles, marked with the in business processes. They are organized
name of the entity type. Figure 3.24 shows an according to the dimensions data visibility, data
entity type Orders at the centre of the diagram. interaction, data transfer, and data-based
Other entity types in the sample application routing.
domain are customers and products. The
attributes are represented as ellipsoids attached
to entity types.
14

15. 2/28/2013
57 58
• Data visibility is very similar to the concept of • Workflow data: The data object is visible to all
scope in programming languages because it activities of a given business process, but access
characterizes the area in which a certain data is restricted by the business process
object is available for access. The most management system, as defined in the business
important workflow data patterns regarding process model.
data visibility are as follows.
• Task data: The data object is local to a
• Environment data: The data object is part of
particular activity; it is not visible to other
the business process execution environment; it
activities of the same process or other processes.
can be accessed by process activities during
• Block data: The data object is visible to all process enactment.
activities of a given subprocess.
59 60
DATA INTERACTION PATTERNS DATA TRANSFER
• Data interaction patterns describe how data • Data transfer is the next dimension to
objects can be passed between activities and consider. Data transfer can be performed by
processes. Data objects can be communicated passing values of data objects and by passing
between activities of the same business references to data objects. These data
process, between activities and subprocesses transfer patterns are very similar to call-by-
of the same business process, and also value and call by- reference, concepts used in
between activities of different business programming languages to invoke
processes. Data can also be communicated procedures and functions.
between the business process and the
business process management system.
15

16. 2/28/2013
61 62
• The levels of abstraction in organization
3.8 MODELLING ORGANIZATION modelling are shown in Figure 3.25. As in
process modelling and data modelling, the meta-
model level provides the means to express
• An important task of a business process models, in this case organizational models.
management system is the coordination of • Concepts at this level are positions, roles, teams,
work among the personnel of an enterprise. and relationships between positions like
To fulfill this, the system has to be provided supervisor. In organization modelling, there are
with information on the organizational a few formal rules on how to express
structures in which the business process will organizational structures, as well as notations to
execute. express them.
63 64
• Sample Organizational chart
16

17. 2/28/2013
65 66
• Each work item is associated with exactly one RESOURCE ALLOCATION
activity instance. When a knowledge worker
• The assignment of process participants to
completes the activity instance, the business activities in a business process can be classified
process management system is informed, so that by resource patterns.
the process instance can be continued • Direct Allocation: In direct allocation, an
accordingly. individual person, rather than a position in an
• In order to discuss the resource allocation organization, is allocated to all activity instances
principles, a state transition diagram of work of a particular activity model. This resource
items is considered, and a relationship of activity allocation is useful in cases where there is
instances to the respective state transitions is exactly one person who is suitable for
provided. performing these activities, such as the
chairperson of a company, who has to finally
decide on investments exceeding a certain
threshold.
67 68
• Role-Based Allocation: Role-based allocation • The mapping of role information to specific
is the standard way of allocating work to the knowledge workers is called role resolution.
members of organizations. It is based on the Current information on the availability of the
understanding that all members of a certain role knowledge worker is used during role resolution.
are somehow functionally equivalent, so that any • There are two ways of realizing role-based
member of the role can perform a given unit of allocation.
work. 1. when an activity instance enters the ready state,
• To each activity model in a business process the work item is communicated to the members
model, a role is assigned, indicating that all of the group. Once one member of the group
members of the role are capable of performing selects a work item, the work items associated
the respective activity instances. with the other group members are deleted.
17

18. 2/28/2013
69 70
2. only one person is selected to perform the 2. by role resolution at run time of the business
activity instance, so only one work item is
created. process, only available persons are selected to
• Advantages of roll base allocation perform activities. This approach avoids situations
1.The business process model does not need to be in which persons are selected to perform activity
changed when there are changes in the
personnel, i.e., employees retire and new instances that are currently not available, for
employees are hired. When using direct instance, due to meetings or absence. In direct role
allocation, any change in the personnel related
resolution, when the person is not available, there is
to the directly allocated persons would result in
a change in the business process model. no way of continuing the business process.
71 72
• Deferred Allocation: In deferred allocation, • Authorization: Authorization allocates
the decision about who performs an activity persons to activity instances based on their
instance is only made at run time of the business positions. So, a list of positions is enumerated
process. To this end, there is no distinction that specifies the persons who can perform the
between deferred allocation and role-based activity instance. This could also be achieved by
allocation. However, in deferred allocation, adding a new role that captures the
rather than using the role information defined authorization.
during design time, the allocation is performed • A specific type of authorization that uses
as an explicit step in the business process, and capabilities of the knowledge worker to perform
not influenced by role information. allocation is also possible.
18

19. 2/28/2013
73 74
• Separation of Duties: The separation of • Case Handling: In the case handling allocation
duties allocation scheme relates different scheme, certain activities in a business process
allocations within one business process. For require an understanding of the overall case. In
instance, a document needs to be signed and these environments, it is useful that the same
countersigned by two employees with a common knowledge worker deals with all activities of one
role. In role-based allocation, these activities business process instance. This avoids errors
could be performed by the same employee. and reduces processing time, because the
Separation of duties allows relating allocations knowledge worker already knows the case, and
in a way that this is ruled out, so that each so can solve the issues at hand more efficiently
document is signed by two different employees. than a colleague to whom the case is not known.
75 76
• History-Based Allocation: The idea of • While this is not part of a role specification, this
history-based allocation is that a person is information needs to be represented in the
allocated to an activity instance based on what business process management system so that it
this person worked on previously, i.e., on the can decide on the allocation based on the history
history of the activity instance that he or she and personal experiences. This allocation
completed. This includes other business process scheme is useful for realizing a “one face to the
instances. The goal is to allocate work to persons customer” strategy, in which for each customer
according to their personal experiences and there is a dedicated individual responsible for all
expertise that is not represented in the role aspects of communication with it.
information.
19

20. 2/28/2013
77 78
• Organizational Allocation: If organizational 3.9 MODELLING OPERATION
allocation is used, not roles but the positions
• During the enactment of human interaction
within the overall organization are used to workflows, knowledge workers perform activity
allocate activity instances. For instance, to instances. When a knowledge worker starts working
authorize expenditure, the manager of the on a specific activity, the respective application
organizational unit that requested the program is started, and the input data as specified in
expenditure needs to approve. Depending on the the process model is transferred to that application
program. When the knowledge worker completes
particular language used to express that activity, the output data generated is collected
organizational allocation, complex allocation in the output parameters. These parameter values
rules can be realized, all of which take advantage can then be stored in the application program. They
of the organizational structure of the company. can also be transferred by the business process
management system to the next activity, as specified
in the business process model.
79 80
• The heterogeneous nature of information • The operational perspective includes:
technology landscapes led to various kinds of ▫ invocation environment of application
interface definitions, most of which did not programs,
prove to be compatible. With the advent of ▫ the definition of the input and output parameters
service-oriented computing, the operational of the application program,
aspects of business processes are represented by ▫ and their mapping to input and output
services, providing the required uniformity. parameters of business process activities.
• Therefore, functional requirements need to be
detailed in order for us to evaluate whether a
certain software system provides the required
functionality in the context of a business
process.
20

21. 2/28/2013
81 82
• This perspective is not limited to functional 3.10 BUSINESS PROCESS FLEXIBILITY
requirements. Non-functional requirements also
• The quest for flexibility can be regarded as the
need to be represented, for instance, security
main driving force behind business process
properties and quality of service properties of
management, both at an organizational level,
the invoked applications or services, such as
where strategic business processes are
execution time and uptime constraints. In
investigated, and at an operational level, where
service-oriented architectures, these properties
human interaction workflows and system
are typically specified in service-level
workflows are important concepts for realizing
agreements between collaborating business
business processes.
partners. These service-level agreements are
• According to Wikipedia, flexibility refers to the
part of a legal contract that the parties sign.
“ability to easily bend an object or the
ability to adapt to different
circumstances.”
83 84
• In today’s dynamic market environments, • Different aspects have to be taken into account
“different circumstances” are induced by when considering flexibility. First of all,
changes in the market environment of the flexibility is provided by explicit representation
company. Business processes are objects that of business processes, because adaptations of
need to adapt easily to changes. Since products explicit, graphically specified business processes
that companies provide to the market are is much easier than adaptation of written
generated by business processes, flexible organizational procedures or business policies
business processes are an important asset for buried in software code.
coping with market changes in an effective
manner.
21

22. 2/28/2013
85 86
• In typical workflow environments, such as Explicit Process Representations
system workflows and human interaction • Business process management systems are
workflows, information systems are required for created to narrow the gap between business
enacting workflow activities. The interfaces to goals and their realization by means of
these systems might be hardcoded in the information technology. The main way to
adapters of the workflow management system. provide this flexibility is based on explicit
In dynamic software landscapes, where representations of business processes at
functionality is provided through standardized different levels. While organizational business
interfaces, the ability to change the binding of processes have a coarse-grained structure and
are typically specified textually by forms,
particular software to workflow activities is
operational business processes consist of process
another source of flexibility. activities, and execution constraints that relate
them.
87 88
This process features a sequence of activities,
• Explicit process representations provide where the first activity to store the order is
flexibility, since changes to the current process preceded by a start event. After the order is
can be discussed and agreed upon by the stored the inventory is checked. This version of
different stakeholders involved in the design of the business process rules that the shipment is
the business process. In this context, flexibility is prepared only after the invoice is sent and the
achieved by changes at the business process funds are received. Finally, the goods are shipped
model level that are immediately translated to and the process terminates.
actual business process instances.
22

23. 2/28/2013
89 90
Discussing the problem of the process
• Due to the somewhat cautious policy realized by
the business process— prepare shipment only instances, the stakeholders find out that
after receiving the funds—business process concurrency can be exploited within the
instances based on this process model might process. If activities can be executed
suffer from long processing times, resulting in concurrently, their order of execution is
insufficient customer satisfaction. irrelevant.
• In order to solve this problem, the process
owner starts a review of this business process by
inviting process participants and process
consultants to a joint workshop. The business
process model is used as a communication
platform for these stakeholders at this
workshop.
91 92
• By associating roles with activity models at
Organizational Modelling design time and mapping roles to personnel that
is skilled, competent, and available to perform
• In the case of human interaction workflows, the the activity at run time, flexibility is improved,
enactment environment of the business process because changes in the personnel structure of
has to take into account the organizational the organization do not affect the business
structure of the company that runs the business processes.
process. Flexibility in organizational modelling
• For instance, absent knowledge workers are not
is achieved by assigning roles to process
with associated with specific activity instances,
activities, and not to specific individuals.
as are persons who are currently available.
23

24. 2/28/2013
93 94
• Thereby, the dynamic aspect in the
organization—knowledge workers might be
temporarily absent or there might be changes in
the work force—can be represented at the model
level. Consequently, changes in the personnel
are hidden from the process, as long as the roles
defined in the model can actually be filled by
persons in the organization.
95 96
• There are different options for selecting a
Selection of Business Partners in
particular shipper. The selection can be done
Process Choreographies before a particular process instance starts. This
• Consider a business process choreography with alternative is useful if sufficient information on
multiple business partners, each of which plays a the goods to be shipped is available before the
specific role in the choreography. If there is a process starts.
role Shipper specified according to the • In scenarios where only during run time of the
requirements for shipping goods, it can be process instance are the goods and the sender
bound to specific enterprises that can perform and receiver determined, the dynamic selection
the work. Additional flexibility is gained because of a shipper is useful. Based on the information
the organizations participating in a on the shipment and on its additional
choreography are not hardwired, but
represented at the model level. properties—such as dangerous goods—an
appropriate shipper can be selected at run time.
24

25. 2/28/2013
97 98
Standardized Software Interfaces
• Standardized interfaces to existing software
systems are another means of flexibility in
business process management. A variety of
techniques to specify software interfaces are
known from software engineering and software
architectures. It is a key concept to decouple the
use of a software component from its
implementation, i.e., to hide implementation
details from usage information, following the
information hiding principle.
99 100
• In the context of business process management,
standardized software interfaces are of crucial
importance in system workflows, and also in
human interaction workflows, since the overall
process structure can be decoupled from the
implementation of particular activities realized
by software components.
• There are two variations: the software system
realizing a particular activity can be defined at
design time of the process or at run time of the
process instances.
25

26. 2/28/2013
101 102
3.11 ARCHITECTURE OF PROCESS
• Business Process Environment: The
EXECUTION ENVIRONMENTS business process environment triggers the
instantiation and enactment of process instances
• The architecture model contains: based on process models.
• Business Process Modelling: The business
process modelling subsystem is used for creating
• Business Process Model Repository: The
business process models, containing information
business process model repository holds
on activities, their operations, and the structure
business process models that are created by the
of the business process. This architecture
business process modelling component.
subsystem can be realized by business process
modelling tools.
103 104
• Process Engine: The process engine is • Service Providers: Service providers host
responsible for instantiating and controlling the application services that realize business process
execution of business processes. It is the core activities. In the architecture model, service
component of a business process management providers represent an abstract entity that
system. This component is triggered by the subsumes not only Web service providers but
business process environment. It uses process also knowledge workers that realize particular
models to instantiate and control the enactment activities in business processes. The
of process instances. To execute a particular organizational and technical information that
activity instance, it calls entities that act as the process engine needs in order to determine
providers of the required functionality. In a and access the service provider is also stored in
service-oriented architecture, service providers the business process model repository.
are called to execute individual services that
realize business process activities.
26