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

Introduction to Workflows and WFMS b Management of business processes from the perspective of computing (IT) b WFMS - software packages for managing business processes b 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 ? b new rules - design business process in a more abstract way without considering implementation; design IS and the organization hand in hand

What the course contains ? b reference framework for defining business processes b discussion of analytical methods b 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) b 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) b methodology for developing workflow applications b case studies of workflow systems

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

Classification of Information Systems b 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) b Office Information Systems b Database Management Systems b Transaction Processing Systems b Knowledge Management Systems b Decision Support Systems b Control Systems b Workflow Management Systems

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

Why Business Process Redesign ? b IT has a role to play in a way how business processes are organized b why this is good ? - because every algorithm defines a process b processes can be defined and analyzed clearly b definition of a process is important to decide whether to implement a process b will 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 animationsimulation techniques, computer animation

Organizational Paradigm Shift b from ‘capacity utilization’ - i.e. the more you produce the better b to ‘customer care’ - i.e. the more (satisfied) customer you have the better b 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 ‘computer applications’to build a bridge between ‘people’s work’ and ‘computer applications’

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

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

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

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

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

How to allocate staff into departments? b 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 b the functional department - performs interdependent group of tasks, each often requiring the same skills; head responsible for the work of the department (accounting, marketing) b process or production departments - department is responsible for a complete business process

Three Good Reasons for Using Petri net- based WFMS b Reason 1: Formal Semantics despite the Graphical Nature; Petri nets can be used to model primitives defined by WfMC b 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 b Reason 3: Abundance of Analysis Techniques and related Software Tools

Reasons for Using State-based Description for WFMS b 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) b 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) b 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 b Reason 4: Moving a case from one location to another (IOWF) is easy - transfer of tokens and triggers

Mapping Workflow Concepts onto Petri nets b process - is specified as a specific Petri net b conditions - are represented as places of Petri nets b tasks - are represented as transitions of Petri net b routing - a specific path of case processing through Petri net describing the process b case - represented as a token or set of tokens located in various places of Petri nets b 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

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

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

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