CIS 581 CIS 581 Design and Verification of Design and Verification of Information Systems (DVIS), Information Systems (DVIS), Spring 2003, lectures 1-2Spring 2003, lectures 1-2

elementary concepts of workflowselementary concepts of workflows workflow = business processworkflow = 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 workflowsthree dimensions of workflows subdivision of processessubdivision of processes organizational structuresorganizational structures mapping workflow concepts onto Petri netsmapping workflow concepts onto Petri nets architectures of inter-organizational workflowsarchitectures of inter-organizational workflows

Introduction to Workflows and Introduction to Workflows and WFMSWFMS

Management of business processes from the Management of business processes from the perspective of computing (IT)perspective of computing (IT)

WFMSWFMS - software packages for managing business - software packages for managing business processesprocesses

old golden rulesold 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 rulesnew 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 handdesign IS and the organization hand in hand

What the CIS 581 course What the CIS 581 course contains ?contains ?

reference frameworkreference framework for defining business processes for defining business processes discussion of discussion of analytical methodsanalytical methods Petri netsPetri nets are extensively used to define and analyze are extensively used to define and analyze

complex processes - PNs can facilitate processes by complex processes - PNs can facilitate processes by non-experts (communication between designers and non-experts (communication between designers and users + existence of software tools)users + existence of software tools)

workflow management systemsworkflow 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)

methodologymethodology for developing workflow applications for developing workflow applications case studies case studies of workflow systemsof workflow systems

What the CIS 581 course What the CIS 581 course contains, ctnd ?contains, ctnd ?

organization of workflowsorganization of workflows management of resourcesmanagement of resources that contribute to business that contribute to business

processesprocesses static and dynamic static and dynamic techniques to analyze workflowstechniques to analyze workflows analysis and properties of analysis and properties of inter-organizational inter-organizational

workflowsworkflows workflows and electronic commerceworkflows and electronic commerce examples of WFMS/toolsexamples of WFMS/tools - Renew, Woflan, Design/CPN - Renew, Woflan, Design/CPN WfMC - Workflow Management CoalitionWfMC - Workflow Management Coalition - to develop - to develop

standard terminology and standard interfaces for standard terminology and standard interfaces for WFMSWFMS

Classification of Information Classification of Information SystemsSystems

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 SystemsOffice Information Systems Database Management SystemsDatabase Management Systems Transaction Processing SystemsTransaction Processing Systems Knowledge Management SystemsKnowledge Management Systems Decision Support SystemsDecision Support Systems Control SystemsControl Systems Workflow Management SystemsWorkflow Management Systems

Organizing WorkflowsOrganizing Workflows

role of work in societyrole 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 economysupply-driven economy to to demand-driven demand-driven economyeconomy (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 shiftorganizational paradigm shift))

reference frameworkreference framework = = ontology of processes ontology of processes = a = a system of defined terms that describe particular field of system of defined terms that describe particular field of knowledgeknowledge

objectivesobjectives: 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 processes; to describe the functionality and architecture of WFMSarchitecture 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 organizedprocesses are organized

why this is good ?why this is good ? - because every algorithm - because every algorithm defines a processdefines a process

processesprocesses 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 processwhether to implement a process will the process work properlywill the process work properly ? ?

• analyze the processanalyze the process• use formal methods to identify properties or lack of themuse formal methods to identify properties or lack of them• simulation techniques, computer animation simulation techniques, computer animation

Organizational Paradigm ShiftOrganizational Paradigm Shift

from ‘from ‘capacity utilization’capacity utilization’ - i.e. the more you - i.e. the more you produce the betterproduce the better

to ‘to ‘customer care’customer care’ - i.e. the more customer - i.e. the more customer you have the betteryou have the better

WFMS shouldWFMS 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 WorkflowsFundamental Concepts of Workflows

tasktask - logical, indivisible, unit of work - logical, indivisible, unit of work casecase - examples: insurance claim, mortgage - examples: insurance claim, mortgage

application; case always has a particular stateapplication; case always has a particular state processprocess - how to carry out a particular category of - how to carry out a particular category of

casescases atomicityatomicity - tasks of work may be assumed to be atomic - tasks of work may be assumed to be atomic granularity of tasksgranularity of tasks - discretization of work - discretization of work economy of scale economy of scale - one process serves many cases- one process serves many cases statestate - composed of three elements: - composed of three elements:

• the values of relevant the values of relevant case attributescase attributes that change as the case that change as the case progresses being processedprogresses being processed

• the the conditionsconditions that have been fulfilled that have been fulfilled• the the contentcontent of the case of the case

Fundamental Concepts of Workflows, Fundamental Concepts of Workflows, ctnd. ctnd.

routingrouting - i.e. routing the case; the life cycle of a - i.e. routing the case; the life cycle of a case is laid down in the processcase is laid down in the process

work itemwork item = case + task; actual piece of work; = case + task; actual piece of work; certain workitems can only be transformed into an certain workitems can only be transformed into an activity once they have been triggeredactivity once they have been triggered

activityactivity = case + task + resource; i.e. actual = case + task + resource; i.e. actual performance of a piece of workperformance of a piece of work

enactment of a caseenactment of a case - triggers are required: - triggers are required:• a resource initiativea resource initiative (employee taking a work item from a (employee taking a work item from a

tray)tray)• an external eventan external event (arrival of a message) (arrival of a message)• a time signala time signal (the generation of a list of orders at 6 pm] (the generation of a list of orders at 6 pm]

Subdivision of processesSubdivision of processes

primaryprimary - to produce products or services - to produce products or services (production processes); they deal with cases (production processes); they deal with cases for a customer; customer-oriented even a for a customer; customer-oriented even a customer is not knowncustomer is not known

secondarysecondary - support primary processes - support primary processes (support processes) - maintaining the means (support processes) - maintaining the means of production, personnel managementof production, personnel management

tertiarytertiary - 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 WorkflowThree dimensions of Workflow

case dimensioncase 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 dimensioncontrol 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 casesystematically deal with a case

resource dimension - resource dimension - human and technical human and technical resources needed to process a caseresources needed to process a case

Organizational StructuresOrganizational Structures

the hierarchical organizationthe hierarchical organization - typically - typically functional or capacity groupsfunctional or capacity groups

the matrix organizationthe matrix organization - used by building - used by building contractors, installation firms, software contractors, installation firms, software houses, typically within one single companyhouses, 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 organizationactors not working in the same organization

How to allocate staff into How to allocate staff into departments?departments?

the capacity groupthe 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, engineersexample - typists, maintenance, engineers

the functional departmentthe functional department - performs - performs interdependent group of tasks, each often requiring interdependent group of tasks, each often requiring the same skills; head responsible for the work of the the same skills; head responsible for the work of the department (accounting, marketing)department (accounting, marketing)

process or production departmentsprocess or production departments - department is - department is responsible for a complete business processresponsible for a complete business process

Three Good Reasons for Using Three Good Reasons for Using Petri net-based WFMSPetri net-based WFMS

Reason 1Reason 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 WfMCto model primitives defined by WfMC

Reason 2Reason 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 suppressedstates between tasks are suppressed

Reason 3Reason 3: Abundance of Analysis : Abundance of Analysis Techniques and related Software ToolsTechniques and related Software Tools

Reasons for Using State-based Reasons for Using State-based Description for WFMSDescription 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 taskscompetitive tasks; two ; two tasks are competitive if both are enabled and only one tasks are competitive if both are enabled and only one of them may be executed (event-based system can of them may be executed (event-based system can not model this situation)not model this situation)

Reason 3:Reason 3: Sometimes it is necessary to Sometimes it is necessary to withdraw a withdraw a casecase; in PNs this means removal of tokens and ; in PNs this means removal of tokens and triggers that correspond to the cancelled casetriggers that correspond to the cancelled case

Reason 4:Reason 4: Moving a caseMoving a case from one location to from one location to another (IOWF) is easy - transfer of tokens and triggersanother (IOWF) is easy - transfer of tokens and triggers

Mapping Workflow Concepts onto Mapping Workflow Concepts onto Petri netsPetri nets

processprocess - is specified as a specific Petri net - is specified as a specific Petri net conditionsconditions - are represented as places of Petri nets - are represented as places of Petri nets taskstasks - are represented as transitions of Petri net - are represented as transitions of Petri net routingrouting - a specific path of case processing through - a specific path of case processing through

Petri net describing the processPetri net describing the process casecase - represented as a token or set of tokens - represented as a token or set of tokens

located in various places of Petri netslocated in various places of Petri nets atomicity of tasksatomicity of tasks - atomic tasks represented as - atomic tasks represented as

transitions can be refined into more detailed Petri transitions can be refined into more detailed Petri net; process or part of a process can be abstracted net; process or part of a process can be abstracted into a single transition or single placeinto a single transition or single place

Common Errors in Process Common Errors in Process DefinitionDefinition

tasks without input and output conditionstasks without input and output conditions dead tasksdead tasks - tasks that can never be - tasks that can never be

carried outcarried out deadlockdeadlock - jamming a case before - jamming a case before

reaching condition called ‘end’reaching condition called ‘end’ livelocklivelock - trapping a case in an endless - trapping a case in an endless

cyclecycle dangling tasksdangling tasks - i.e. activities still take - i.e. activities still take

place after the case has been completedplace after the case has been completed

Fundamental Issues in Fundamental Issues in WorkflowsWorkflows

Basic Definitions of Workflows and WFMSBasic Definitions of Workflows and WFMS Workflow PatternsWorkflow Patterns Workflow vs. InheritanceWorkflow vs. Inheritance Dealing with Change in WorkflowsDealing with Change in Workflows Software Architectures and WorkflowsSoftware Architectures and Workflows Verification of Workflows & WoflanVerification of Workflows & Woflan Inter-organizational Workflows and E-Inter-organizational Workflows and E-

commercecommerce Reference Nets & RenewReference Nets & Renew

Six Basic Software Architectures of Six Basic Software Architectures of Inter-organizational WorkflowsInter-organizational Workflows

Capacity Sharing Architecture (CSA)Capacity Sharing Architecture (CSA) Chained Execution Architecture Chained Execution Architecture

(CEA)(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)