1. CIS 581 Design and Verification of Information Systems (DVIS), Spring 2003, lectures 1-2
elementary concepts of workflows
workflow = business process
BPR - Business Process Redesign (Reengineering)
functions of WMS (Workflow Management Systems)
three dimensions of workflows
subdivision of processes
organizational structures
mapping workflow concepts onto Petri nets
architectures of inter-organizational workflows

2. Introduction to Workflows and WFMS
Management of business processes from the perspective of computing (IT)
WFMS - software packages for managing business processes
old golden rules - first organize then computerize (processes were developed with silent assumption that the business process is managed by people; organizational structure would be developed under which people were allocated tasks; can IS support the work ?
new rules - design business process in a more abstract way without considering implementation; design IS and the organization hand in hand

3. What the CIS 581 course contains ?
reference framework for defining business processes
discussion of analytical methods
Petri nets are extensively used to define and analyze complex processes - PNs can facilitate processes by non-experts (communication between designers and users + existence of software tools)
workflow management systems, i.e. the right information reaches the right person at the right time (generic software packages that can be used in many applications)
methodology for developing workflow applications
case studies of workflow systems

4. What the CIS 581 course contains, ctnd ?
organization of workflows
management of resources that contribute to business processes
static and dynamic techniques to analyze workflows
analysis and properties of inter-organizational workflows
workflows and electronic commerce
examples of WFMS/tools - Renew, Woflan, Design/CPN
WfMC - Workflow Management Coalition - to develop standard terminology and standard interfaces for WFMS

5. Classification of Information Systems
IS are used to reduce people’s workload, esp. in offices (text writing - word processors, drawing - drawing systems, calculating - spreadsheet systems, filing - database systems, communicating information - electronic systems)
Office Information Systems
Database Management Systems
Transaction Processing Systems
Knowledge Management Systems
Decision Support Systems
Control Systems
Workflow Management Systems

6. Organizing Workflows
role of work in society: we work to live, we can not do everything in our life, we are organized in specialized ‘business units’
change from supply-driven economy to demand-driven economy (customers are scarce)
shift of focus from the means of production to the customer (organizational paradigm shift)
reference framework = ontology of processes = a system of defined terms that describe particular field of knowledge
objectives: to define business-management context within which WFMS operate; to model and analyze processes; to describe the functionality and architecture of WFMS

7. Why Business Process Redesign ?
IT has a role to play in a way how business processes are organized
why this is good ? - because every algorithm defines a process
processes can be defined and analyzed clearly
definition of a process is important to decide whether to implement a process
will the process work properly ?
analyze the process
use formal methods to identify properties or lack of them
simulation techniques, computer animation

8. Organizational Paradigm Shift
from ‘capacity utilization’ - i.e. the more you produce the better
to ‘customer care’ - i.e. the more customer you have the better
WFMS should:
make ‘work controllable’,
to encourage communication between employees,
to build a bridge between ‘people’s work’ and ‘computer applications’

9. Fundamental Concepts of Workflows
task - logical, indivisible, unit of work
case - examples: insurance claim, mortgage application; case always has a particular state
process - how to carry out a particular category of cases
atomicity - tasks of work may be assumed to be atomic
granularity of tasks - discretization of work
economy of scale - one process serves many cases
state - composed of three elements:
the values of relevant case attributes that change as the case progresses being processed
the conditions that have been fulfilled
the content of the case

10. Fundamental Concepts of Workflows, ctnd.
routing - i.e. routing the case; the life cycle of a case is laid down in the process
work item = case + task; actual piece of work; certain workitems can only be transformed into an activity once they have been triggered
activity = case + task + resource; i.e. actual performance of a piece of work
enactment of a case - triggers are required:
a resource initiative (employee taking a work item from a tray)
an external event (arrival of a message)
a time signal (the generation of a list of orders at 6 pm]

11. Subdivision of processes
primary - to produce products or services (production processes); they deal with cases for a customer; customer-oriented even a customer is not known
secondary - support primary processes (support processes) - maintaining the means of production, personnel management
tertiary - managerial processes that direct and coordinate primary and secondary processes, maintenance of contacts with financiers and stakeholders

12. Three dimensions of Workflow
case dimension - workflow systems deal with cases; cases have case types (such as insurance claim, mortgage application, tax return, patient in a hospital)
control flow dimension - partial order of tasks within a specific case, i.e. how to systematically deal with a case
resource dimension - human and technical resources needed to process a case

13. Organizational Structures
the hierarchical organization - typically functional or capacity groups
the matrix organization - used by building contractors, installation firms, software houses, typically within one single company
the network organization - similar to matrix organization except that typically composed of actors not working in the same organization

14. How to allocate staff into departments?
the capacity group - people with the same skills, they are interchangeable; head of the department keeps its members ‘up-to-date’ (through training); example - typists, maintenance, engineers
the functional department - performs interdependent group of tasks, each often requiring the same skills; head responsible for the work of the department (accounting, marketing)
process or production departments - department is responsible for a complete business process

15. Three Good Reasons for Using Petri net-based WFMS
Reason 1: Formal Semantics despite the Graphical Nature; Petri Nets can be used to model primitives defined by WfMC
Reason 2: State-based instead of Event-based (today’s WFMS are event based, i.e. tasks/transitions are modeled and states between tasks are suppressed
Reason 3: Abundance of Analysis Techniques and related Software Tools

16. Reasons for Using State-based Description for WFMS
Reason 1: It allows for a clear distinction between the enabling of a task and the execution of a task (issue of task triggering: automatic, user, message, time)
Reason 2: Possibility of competitive tasks; two tasks are competitive if both are enabled and only one of them may be executed (event-based system can not model this situation)
Reason 3: Sometimes it is necessary to withdraw a case; in PNs this means removal of tokens and triggers that correspond to the cancelled case
Reason 4: Moving a case from one location to another (IOWF) is easy - transfer of tokens and triggers

17. Mapping Workflow Concepts onto Petri nets
process - is specified as a specific Petri net
conditions - are represented as places of Petri nets
tasks - are represented as transitions of Petri net
routing - a specific path of case processing through Petri net describing the process
case - represented as a token or set of tokens located in various places of Petri nets
atomicity of tasks - atomic tasks represented as transitions can be refined into more detailed Petri net; process or part of a process can be abstracted into a single transition or single place

18. Common Errors in Process Definition
tasks without input and output conditions
dead tasks - tasks that can never be carried out
deadlock - jamming a case before reaching condition called ‘end’
livelock - trapping a case in an endless cycle
dangling tasks - i.e. activities still take place after the case has been completed

19. Fundamental Issues in Workflows
Basic Definitions of Workflows and WFMS
Workflow Patterns
Workflow vs. Inheritance
Dealing with Change in Workflows
Software Architectures and Workflows
Verification of Workflows & Woflan
Inter-organizational Workflows and E-commerce
Reference Nets & Renew

20. Six Basic Software Architectures of Inter-organizational Workflows
Capacity Sharing Architecture (CSA)
Chained Execution Architecture (CEA)
Subcontracting Architecture (SCA)
Case Transfer Architecture (CTA)
Extended Case Transfer Architecture (ECTA)
Loosely Coupled Architecture (LCA)