1. Information Technology IMS5024 Information Systems Modelling Event-driven modelling

2. School of Information Management & Systems 8.2 Content BRD SAP R/3 Place in ISD Reading list for next week

3. School of Information Management & Systems 8.3 Different perspectives Process Data Behaviour / Stimulus response – how system reacts to external and internal events Difference

4. School of Information Management & Systems 8.4 Techniques State transition diagrams (STD) Business rules diagram (BRD) Event-driven process chain (EPC) methodology Petri nets Finite state machines

5. School of Information Management & Systems 8.5 Key constructs of BRD State Event Condition SignalBlob

6. School of Information Management & Systems 8.6 Definition of a business rule “An explicit state change context in an organisation which describes the states, conditions and signals associated with events that either change the state of a human activity system so that subsequently it will respond differently to external stimuli or reinforce the constraints which govern a human activity system.” McDermid 1998

7. School of Information Management & Systems 8.7 Business rule types Implementation rules Processing rules Policy rules

8. School of Information Management & Systems 8.8 Steps in creating BRD Identify candidate business (policy) rules Identify candidate events and signals Identify candidate objects in the problem situation Construct object life histories (OLH) for each object identified Construct user business rule diagrams (UBRD) Construct business rules diagram Construct event specification table (EST)

9. School of Information Management & Systems 8.9 Example candidate business (policy) rules Orders sent by mail or telephone Omissions on order line leads to deletion Available credit >= order value to accept order else reject Available stock qty >= order qty to accept order otherwise reject One invoice for one order Sum of payments = order value – sum of credit notes One order may have many credit notes

10. School of Information Management & Systems 8.10 Further examples Many payments per invoice possible Overdue invoices occur 30 days after statement If product not carried reject item If unobtainable multiples reject item New order created for outstanding items Only good customers may obtain credit orders Credit balance reduced for all items on an order including outstanding items

11. School of Information Management & Systems 8.11 Example of candidate list of business events and signals Receive customer orderT Delete lineE Reject orderE Create new orderE Send invoiceM Generate credit noteE Receive paymentT Create outstanding itemE Create new customerE Change status to good customerE Change status to bad customerE

12. School of Information Management & Systems 8.12 Example object life history Customer Temp cust Good cust Bad cust

13. School of Information Management & Systems 8.13 SAP R/3 Best practice processes – then focus on unique aspects Blueprint used as reference model Business process takes center stage

14. School of Information Management & Systems 8.14 Blueprint Help organisations to define needs, develop solutions and optimize their processes Do not need to start from scratch Customisation possible Include functions, process, information flow and organisation views Business processes are shown in the Event-driven process chains

15. School of Information Management & Systems 8.15 Modelling approach Define / redefine the organisations goals Create a model to reflect the goals Develop unique applications Implement the applications

16. School of Information Management & Systems 8.16 SAP approach Map company processes to the blue print (reflect “best practice”) Define target situation Focus on unique aspects Customize and configure

17. School of Information Management & Systems 8.17 Key elements of SAP blueprint Events (when should something be done?) Tasks or functions (what should be done?) Organisation (who should do what?) Communication (What information is required to the right task?)

18. School of Information Management & Systems 8.18 Event-driven process chain (EPC) methodology (1) Event e.g.. Goods arrived Task / function e.g.. Verify goods Organisation e.g. Good receiving dept Information / resource e.g. Delivery note

19. School of Information Management & Systems 8.19 Event-driven process chain (EPC) methodology (2) Xor Process path Logical operator Control flow Information/material flow Resource/organisation unit assignment

20. School of Information Management & Systems 8.20 Legend EPC is the central view Event always triggers a task Start and end with an event Organisational units are added Navigation between process models by start and final event

21. School of Information Management & Systems 8.21 Example of an EPC refer Davis, 2001 fig 9.13

22. School of Information Management & Systems 8.22 Elements of EPC Event set of values for which it has a predefined action if set of values occurs eg credit limit exceeded IF current document is sales order AND IF current customer has credit limit AND IF sales order value > customer credit limit THEN issue warning to user entering sales order

23. School of Information Management & Systems 8.23 Elements of EPC Function brings about a transformation from an initial state to a target state eg verify order, convert currency purpose is to do something activated by one of a set of events operates on information from many sources

24. School of Information Management & Systems 8.24 Event Driven Process Chain Order received order entered Cost calculated Enter order Calculate cost It couldn’t be simpler! after Fig 7.2 Davis

25. School of Information Management & Systems 8.25 Elements of EPC Organisational Unit element used in organisational structure - department, section, person eg sales dept., finance manager can be defined in terms of material groups processed, markets served eg steelworks division, juvenile apparel system organisation units

26. School of Information Management & Systems 8.26 Elements of EPC Information, material or resource object real world objects business objects, entities resource objects eg. energy, services, purchase order, information system

27. School of Information Management & Systems 8.27 X Elements of EPC AND - all inputs to symbol must be true for output to occur XOR (exclusive OR) - one input, but not both, must be true for output to occur OR (either or both) - either input will suffice on its own, or both may be true to allow output Logical Operators

28. School of Information Management & Systems 8.28 Elements of EPC Control Flow - time and/or sequence ordering, interdependence of event and function Information or Material Flow - read, change or write data; movement of material Resource or Organisational Unit Assignment - unit or staff resource processes or is processed by a function

29. School of Information Management & Systems 8.29 Modelling decisions X Order received Check product ordered Product A required Product B required Manufacture Product A Manufacture Product B

30. School of Information Management & Systems 8.30 Rules and Process Flow not all processes are strictly sequential flows business rules govern processes rules are tested by conditional branches if.TRUE. then do this if.FALSE. then do that (or do nothing)

31. School of Information Management & Systems 8.31 Other views Component model – describe what is done Organisation model – Who does what and who is responsible Data model – what is needed to do something Interaction model – what information must be exchanged between different units

32. School of Information Management & Systems 8.32 References Johnstone & McDermid (1999) “Extending and Validating the Business Rules Diagram Method.” Proceedings of 10 th Australasian Conference on Information Systems. Davis (2001) “Business Process Modelling with ARIS.” Springer-Verlag.

33. School of Information Management & Systems 8.33 Reading for next week Checkland and Scholes (1990) Chapters 1 and 2