CIS 581
CIS 581
Design and Verification of
Design and Verification of
Information Systems (DVIS),
Information Systems (DVIS),
lectures 1-2
lectures 1-2
elementary concepts of workflows
elementary concepts of workflows
workflow = business process
workflow = business process
BPR - Business Process Redesign (Reengineering)
BPR - Business Process Redesign (Reengineering)
functions of WMS (Workflow Management
functions of WMS (Workflow Management
Systems)
Systems)
three dimensions of workflows
three dimensions of workflows
subdivision of processes
subdivision of processes
organizational structures
organizational structures
mapping workflow concepts onto Petri nets
mapping workflow concepts onto Petri nets
architectures of inter-organizational workflows
architectures of inter-organizational workflows
Introduction to Workflows and
Introduction to Workflows and
WFMS
WFMS
Management of business processes from the
Management of business processes from the
perspective of computing (IT)
perspective of computing (IT)
WFMS
WFMS
- software packages for managing business
- software packages for managing business
processes
processes
old golden rules
old golden rules
- first organize then computerize
- first organize then computerize
(processes were developed with silent assumption
(processes were developed with silent assumption
that the business process is managed by people;
that the business process is managed by people;
organizational structure would be developed under
organizational structure would be developed under
which people were allocated tasks; can IS support
which people were allocated tasks; can IS support
the work ?
the work ?
new rules
new rules
- design business process in a more
- design business process in a more
abstract way without considering implementation;
abstract way without considering implementation;
design IS and the organization hand in hand
design IS and the organization hand in hand
What the CIS 581 course
What the CIS 581 course
contains ?
contains ?
reference framework
reference framework
for defining business processes
for defining business processes
discussion of
discussion of
analytical methods
analytical methods
Petri nets
Petri nets
are extensively used to define and analyze
are extensively used to define and analyze
complex processes - PNs can facilitate processes by non-
complex processes - PNs can facilitate processes by non-
experts (communication between designers and users +
experts (communication between designers and users +
existence of software tools)
existence of software tools)
workflow management systems
workflow management systems
, i.e. the right
, i.e. the right
information reaches the right person at the right time
information reaches the right person at the right time
(generic software packages that can be used in many
(generic software packages that can be used in many
applications)
applications)
methodology
methodology
for developing workflow applications
for developing workflow applications
case studies
case studies
of workflow systems
of workflow systems
What the CIS 581 course
What the CIS 581 course
contains, ctnd ?
contains, ctnd ?
organization of workflows
organization of workflows
management of resources
management of resources
that contribute to business
that contribute to business
processes
processes
static and dynamic
static and dynamic
techniques to analyze workflows
techniques to analyze workflows
analysis and properties of
analysis and properties of
inter-organizational
inter-organizational
workflows
workflows
workflows and electronic commerce
workflows and electronic commerce
examples of WFMS/tools
examples of WFMS/tools
- Renew, Woflan, Design/CPN
- Renew, Woflan, Design/CPN
WfMC - Workflow Management Coalition
WfMC - Workflow Management Coalition
- to develop
- to develop
standard terminology and standard interfaces for
standard terminology and standard interfaces for
WFMS
WFMS
Classification of Information
Classification of Information
Systems
Systems
IS are used to reduce people’s workload, esp. in offices (text
IS are used to reduce people’s workload, esp. in offices (text
writing - word processors, drawing - drawing systems,
writing - word processors, drawing - drawing systems,
calculating - spreadsheet systems, filing - database systems,
calculating - spreadsheet systems, filing - database systems,
communicating information - electronic email systems)
communicating information - electronic email systems)
Office Information Systems
Office Information Systems
Database Management Systems
Database Management Systems
Transaction Processing Systems
Transaction Processing Systems
Knowledge Management Systems
Knowledge Management Systems
Decision Support Systems
Decision Support Systems
Control Systems
Control Systems
Workflow Management Systems
Workflow Management Systems
Organizing Workflows
Organizing Workflows
role of work in society
role of work in society
: we work to live, we can not do
: we work to live, we can not do
everything in our life, we are organized in specialized
everything in our life, we are organized in specialized
‘business units’
‘business units’
change from
change from
supply-driven economy
supply-driven economy
to
to
demand-driven
demand-driven
economy
economy
(customers are scarce)
(customers are scarce)
shift of focus from the means of production to the
shift of focus from the means of production to the
customer (
customer (
organizational paradigm shift
organizational paradigm shift
)
)
reference framework
reference framework
=
=
ontology of processes
ontology of processes
= a system
= a system
of defined terms that describe particular field of
of defined terms that describe particular field of
knowledge
knowledge
objectives
objectives
: to define business-management context
: to define business-management context
within which WFMS operate; to model and analyze
within which WFMS operate; to model and analyze
processes; to describe the functionality and architecture
processes; to describe the functionality and architecture
of WFMS
of WFMS
Why Business Process Redesign ?
Why Business Process Redesign ?
IT has a role to play in a way how business
IT has a role to play in a way how business
processes are organized
processes are organized
why this is good ?
why this is good ?
- because every algorithm
- because every algorithm
defines a process
defines a process
processes
processes
can be defined and analyzed clearly
can be defined and analyzed clearly
definition of a process is important to decide
definition of a process is important to decide
whether to implement a process
whether to implement a process
will the process work properly
will the process work properly
?
?
•
analyze the process
analyze the process
•
use formal methods to identify properties or lack of them
use formal methods to identify properties or lack of them
•
simulation techniques, computer animation
simulation techniques, computer animation
Organizational Paradigm Shift
Organizational Paradigm Shift
from ‘
from ‘
capacity utilization’
capacity utilization’
- i.e. the more you
- i.e. the more you
produce the better
produce the better
to ‘
to ‘
customer care’
customer care’
- i.e. the more customer
- i.e. the more customer
you have the better
you have the better
WFMS should
WFMS should
:
:
•
make ‘work controllable’,
make ‘work controllable’,
•
to encourage communication between employees,
to encourage communication between employees,
•
to build a bridge between ‘people’s work’ and
to build a bridge between ‘people’s work’ and
‘computer applications’
‘computer applications’
Fundamental Concepts of Workflows
Fundamental Concepts of Workflows
task
task
- logical, indivisible, unit of work
- logical, indivisible, unit of work
case
case
- examples: insurance claim, mortgage
- examples: insurance claim, mortgage
application; case always has a particular state
application; case always has a particular state
process
process
- how to carry out a particular category of
- how to carry out a particular category of
cases
cases
atomicity
atomicity
- tasks of work may be assumed to be atomic
- tasks of work may be assumed to be atomic
granularity of tasks
granularity of tasks
- discretization of work
- discretization of work
economy of scale
economy of scale
- one process serves many cases
- one process serves many cases
state
state
- composed of three elements:
- composed of three elements:
•
the values of relevant
the values of relevant
case attributes
case attributes
that change as the case
that change as the case
progresses being processed
progresses being processed
•
the
the
conditions
conditions
that have been fulfilled
that have been fulfilled
•
the
the
content
content
of the case
of the case
Fundamental Concepts of Workflows,
Fundamental Concepts of Workflows,
ctnd.
ctnd.
routing
routing
- i.e. routing the case; the life cycle of a case
- i.e. routing the case; the life cycle of a case
is laid down in the process
is laid down in the process
work item
work item
= case + task; actual piece of work; certain
= case + task; actual piece of work; certain
workitems can only be transformed into an activity
workitems can only be transformed into an activity
once they have been triggered
once they have been triggered
activity
activity
= case + task + resource; i.e. actual
= case + task + resource; i.e. actual
performance of a piece of work
performance of a piece of work
enactment of a case
enactment of a case
- triggers are required:
- triggers are required:
•
a resource initiative
a resource initiative
(employee taking a work item from a
(employee taking a work item from a
tray)
tray)
•
an external event
an external event
(arrival of a message)
(arrival of a message)
•
a time signal
a time signal
(the generation of a list of orders at 6 pm]
(the generation of a list of orders at 6 pm]
Subdivision of processes
Subdivision of processes
primary
primary
- to produce products or services
- to produce products or services
(production processes); they deal with cases for
(production processes); they deal with cases for
a customer; customer-oriented even a customer
a customer; customer-oriented even a customer
is not known
is not known
secondary
secondary
- support primary processes (support
- support primary processes (support
processes) - maintaining the means of
processes) - maintaining the means of
production, personnel management
production, personnel management
tertiary
tertiary
- managerial processes that direct and
- managerial processes that direct and
coordinate primary and secondary processes,
coordinate primary and secondary processes,
maintenance of contacts with financiers and
maintenance of contacts with financiers and
stakeholders
stakeholders
Three dimensions of Workflow
Three dimensions of Workflow
case dimension
case dimension
- workflow systems deal with
- workflow systems deal with
cases; cases have case types (such as
cases; cases have case types (such as
insurance claim, mortgage application, tax
insurance claim, mortgage application, tax
return, patient in a hospital)
return, patient in a hospital)
control flow dimension
control flow dimension
- partial order of tasks
- partial order of tasks
within a specific case, i.e. how to
within a specific case, i.e. how to
systematically deal with a case
systematically deal with a case
resource dimension -
resource dimension -
human and technical
human and technical
resources needed to process a case
resources needed to process a case
Organizational Structures
Organizational Structures
the hierarchical organization
the hierarchical organization
- typically
- typically
functional or capacity groups
functional or capacity groups
the matrix organization
the matrix organization
- used by building
- used by building
contractors, installation firms, software
contractors, installation firms, software
houses, typically within one single company
houses, typically within one single company
the network organization
the network organization
- similar to matrix
- similar to matrix
organization except that typically composed of
organization except that typically composed of
actors not working in the same organization
actors not working in the same organization
How to allocate staff into
How to allocate staff into
departments?
departments?
the capacity group
the capacity group
- people with the same skills,
- people with the same skills,
they are interchangeable; head of the department
they are interchangeable; head of the department
keeps its members ‘up-to-date’ (through training);
keeps its members ‘up-to-date’ (through training);
example - typists, maintenance, engineers
example - typists, maintenance, engineers
the functional department
the functional department
- performs
- performs
interdependent group of tasks, each often
interdependent group of tasks, each often
requiring the same skills; head responsible for the
requiring the same skills; head responsible for the
work of the department (accounting, marketing)
work of the department (accounting, marketing)
process or production departments
process or production departments
- department is
- department is
responsible for a complete business process
responsible for a complete business process
Three Good Reasons for Using
Three Good Reasons for Using
Petri net-based WFMS
Petri net-based WFMS
Reason 1
Reason 1
: Formal Semantics despite the
: Formal Semantics despite the
Graphical Nature; Petri Nets can be used
Graphical Nature; Petri Nets can be used
to model primitives defined by WfMC
to model primitives defined by WfMC
Reason 2
Reason 2
: State-based instead of Event-
: State-based instead of Event-
based (today’s WFMS are event based,
based (today’s WFMS are event based,
i.e. tasks/transitions are modeled and
i.e. tasks/transitions are modeled and
states between tasks are suppressed
states between tasks are suppressed
Reason 3
Reason 3
: Abundance of Analysis
: Abundance of Analysis
Techniques and related Software Tools
Techniques and related Software Tools
Reasons for Using State-based
Reasons for Using State-based
Description for WFMS
Description for WFMS
Reason 1:
Reason 1:
It allows for a clear distinction between the
It allows for a clear distinction between the
enabling of a task and the execution of a task (issue of
enabling of a task and the execution of a task (issue of
task triggering: automatic, user, message, time)
task triggering: automatic, user, message, time)
Reason 2:
Reason 2:
Possibility of
Possibility of
competitive tasks
competitive tasks
; two tasks
; two tasks
are competitive if both are enabled and only one of
are competitive if both are enabled and only one of
them may be executed (event-based system can not
them may be executed (event-based system can not
model this situation)
model this situation)
Reason 3:
Reason 3:
Sometimes it is necessary to
Sometimes it is necessary to
withdraw a
withdraw a
case
case
; in PNs this means removal of tokens and triggers
; in PNs this means removal of tokens and triggers
that correspond to the cancelled case
that correspond to the cancelled case
Reason 4:
Reason 4:
Moving a case
Moving a case
from one location to
from one location to
another (IOWF) is easy - transfer of tokens and triggers
another (IOWF) is easy - transfer of tokens and triggers
Mapping Workflow Concepts onto
Mapping Workflow Concepts onto
Petri nets
Petri nets
process
process
- is specified as a specific Petri net
- is specified as a specific Petri net
conditions
conditions
- are represented as places of Petri nets
- are represented as places of Petri nets
tasks
tasks
- are represented as transitions of Petri net
- are represented as transitions of Petri net
routing
routing
- a specific path of case processing through
- a specific path of case processing through
Petri net describing the process
Petri net describing the process
case
case
- represented as a token or set of tokens located
- represented as a token or set of tokens located
in various places of Petri nets
in various places of Petri nets
atomicity of tasks
atomicity of tasks
- atomic tasks represented as
- atomic tasks represented as
transitions can be refined into more detailed Petri net;
transitions can be refined into more detailed Petri net;
process or part of a process can be abstracted into a
process or part of a process can be abstracted into a
single transition or single place
single transition or single place
Common Errors in Process
Common Errors in Process
Definition
Definition
tasks without input and output conditions
tasks without input and output conditions
dead tasks
dead tasks
- tasks that can never be
- tasks that can never be
carried out
carried out
deadlock
deadlock
- jamming a case before
- jamming a case before
reaching condition called ‘end’
reaching condition called ‘end’
livelock
livelock
- trapping a case in an endless
- trapping a case in an endless
cycle
cycle
dangling tasks
dangling tasks
- i.e. activities still take
- i.e. activities still take
place after the case has been completed
place after the case has been completed
Fundamental Issues in
Fundamental Issues in
Workflows
Workflows
Basic Definitions of Workflows and WFMS
Basic Definitions of Workflows and WFMS
Workflow Patterns
Workflow Patterns
Workflow vs. Inheritance
Workflow vs. Inheritance
Dealing with Change in Workflows
Dealing with Change in Workflows
Software Architectures and Workflows
Software Architectures and Workflows
Verification of Workflows & Woflan
Verification of Workflows & Woflan
Inter-organizational Workflows and E-
Inter-organizational Workflows and E-
commerce
commerce
Reference Nets & Renew
Reference Nets & Renew
Six Basic Software Architectures of
Six Basic Software Architectures of
Inter-organizational Workflows
Inter-organizational Workflows
Capacity Sharing Architecture (CSA)
Capacity Sharing Architecture (CSA)
Chained Execution Architecture (CEA)
Chained Execution Architecture (CEA)
Subcontracting Architecture (SCA)
Subcontracting Architecture (SCA)
Case Transfer Architecture (CTA)
Case Transfer Architecture (CTA)
Extended Case Transfer Architecture
Extended Case Transfer Architecture
(ECTA)
(ECTA)
Loosely Coupled Architecture (LCA)
Loosely Coupled Architecture (LCA)
Document Outline