EventDriven Process Chains

1
Event-Driven Process Chains

• Using EPCs to
• design, implement, and control business processes

Source Sheer, Thomas, and Adam, 2005, Modeling
Business Processes Using EPCs, Process Aware
Information Systems, Edited by Dumas, van der
Aalst, and ter Hofstede, New York John Wiley and
Sons, Inc.
2
SAP

• The EPC notation was developed in a collaboration
  between SAP AG and the University of Saarland
  (Professor August-Wilhelm Scheer)
• EPC is the key component of SAP R/3s modeling
  concepts for business process engineering and
  customization
• EPC is supported by
• SAPs NetWeaver System, and by
• SAPs ARIS, an integrated toolset for designing,
  implementing, and controlling business processes

3
Foundations

• EPC is based on the concepts of stochastic
  networks and petri nets
• After the development of the ARIS toolset, the
  basic EPC was extended
• We do not distinguish the EPC from the eEPC,
  because the latter faithfully contains former
• In talking about EPC we mean the eEPC

4
BFOI four views

• Business Flows the business units involved in
  the process including their output and
  communication relationships
• Function Flows the behavior of the process
• Output Flows the results of the process
• Information Flows the interchange of documents

5
1. Business Flows
Example Ordering Process

• This view can be interpreted as a context
  diagram (DFD-paradigm) or as an interaction
  diagram (UML-paradigm)

The sequence of events is not clear Activities
can be added selectively
6
2. Function Flows
Example Ordering Process

• This view characterizes the business process

The sequence of activities is clear
Business units can be added selectively
7
3. Output Flows
Example Ordering Process
ordersupplies
process order
pay
enterorder
planmanufacturing
processorder
manufactureitem
shipitem
sendpayment
manufactureitem
shipitem
Bytes, Bucks, and Boxes

• This view does not characterizes the business
  process

The sequence of activities is not clear
Business units, not included for clarity
8
4. Information Flows
Example Ordering Process
supplier data
inventory data
credit data
supply requirements
order data
payment data
order data
operations data
manufacturing data
invoice amount

• This view can be interpreted as an ERD (Chen,
  1976)

The sequence of activities is nearly clear
An activity may require many information services
An information service may invoke many activities
9
Single Views of the BP

• None of the BFOI views is able to completely
  capture the entire business process
• We must, therefore, combine the views
• Use any one as the basis, and integrate the
  others into it
• Typically one uses the Function Flow as the base
  view

10
Consolidated View
Example Ordering Process
This view is known as Control Flowssolid
arrows control the eventsthrough the use of
logical operators

• In this consolidated view Function Flows are
  enhanced with events

Events trigger information flows, messages
Output Flows are added to complete the view
11
Events

• Events make it possible to better describe the
  business process
• Events describe condition changes
• Events can characterize the results of an
  activity
• Events trigger the next function
• Control Flows (solid arrows) are executed by
  events that they trigger, after which information
  regarding the beginning of the next event is
  transferred to the next entity
• Control Flows determine how functions react to
  events
• Messages can also include additional attributes
  besides information regarding the beginning of
  the event

12
11 Rules for Modeling EPCs

• The three core nodes of an EPC are activities,
  events, and connectors
• The name of an event should reflect its
  characteristic as a point in time
• The name of an activity should reflect the time
  consuming feature of the task
• Connectors are represented by a circle within
  the circle, the connector is defined through the
  corresponding symbol the connector can be split
  into an upper and a lower part, reflecting the
  differences between incoming and outgoing
  connection rules

13
11 Rules for Modeling EPCs

• To clearly define the beginning and ending of a
  business process, every EPC starts and ends with
  one or more events
• An EPC contains at lease one activity
• An EPC can be composed of several EPCs
• Edges are always directed and connect elements in
  the sequence order of the business process being
  modeled

14
11 Rules for Modeling EPCs

• An event cannot be the predecessor or the
  successor of another event
• An activity cannot be the predecessor or the
  successor of another activity
• Each event and each activity has only one
  incoming and/or one outgoing edge

15
Guidelines for Modeling EPCs

• First, determine the exact name of the process to
  be modeled. This is a simple but very important
  step, as it must be clear which process is meant.
  Choose a title everyone agrees on.
• Determine the initial event(s) and the final
  event(s)
• Fill the space between the initial and final
  events with the basic control flow. Use the
  function view model as the basis by focusing on
  verbs.
• Determine one (or more) event(s) for each
  transition between activities make sure each
  event you pick is produced by the preceding
  activity and that it is needed to trigger the
  next activity.
• Check with the 11 Rules for Modeling EPCs
• Last, add the business units, the output flows,
  and the information flows.