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)