1. info1409 2006/7 DMU1 The story so far… Systems Analysis & Design Academic Year 2008/9 Lecture 10

2. info1409 2006/7 DMU2 Lecture Objectives This lecture is to review the work we have done so far in Lectures 1 to 9. We will take a look at a ‘thumbnail sketch’ of the module content in order to consolidate your learning.

3. info1409 2006/7 DMU3 Lecture 1 – What is a system? Lecture 1 introduced the idea of the components of a system. Input/output Process Feedback and feed-forward (controls) System boundary

4. info1409 2006/7 DMU4 Control in systems Inputs Outputs Process Control System Boundary Environment Feed- forward Feed- back Control flows

5. info1409 2006/7 DMU5 We also considered Info systems Information systems operate in terms of: Goals ( the desired long/medium term outcomes) Elements – (the required hardware & software) Inputs – (the type and quantity of data) Outputs – (the result of the processing operations)

6. info1409 2006/7 DMU6 Components of an Information system

7. info1409 2006/7 DMU7 Lecture 2 –How businesses use Info systems Lecture 2 examines modern information systems and how they provide for new types of business operations. Information processing, also includes communication systems and the Internet.

8. info1409 2006/7 DMU8 Impact of the Internet Internet based commerce is called: e-commerce (electronic commerce) or I- commerce (Internet commerce) E-commerce includes 2 main sectors B2C – Business to Consumer B2B – Business to Business

9. info1409 2006/7 DMU9 B2C (Business to Consumer)- Social Effects : Using the Internet, purchasers can go on line to purchase an enormous variety of products and services B2C commerce is changing traditional business models Web designers create attractive sites that increase online sales.

10. info1409 2006/7 DMU10 B2B (Business to Business) Social effects B2B Allows companies to access the Global marketplace (online trading) The volume of B2B transactions is much greater than that of B2C. It enables instant information about market prices and availability.

11. info1409 2006/7 DMU11 Consumer to Consumer C2C - Another innovation is the fact that the Internet can also be used to provide ‘on line auctions’ (Web based providers like EBay form the link between buyers and sellers of all types of personal possessions) This has proved to be a growth area – there are many on line auctions, but EBay is the most well known.

12. info1409 2006/7 DMU12 Lecture 3 – Systems Development Lecture 3 introduces the idea of the Systems Development Life cycle The ‘waterfall’ model is the traditional way to represent structured analysis and design.

13. info1409 2006/7 DMU13

14. info1409 2006/7 DMU14 Lecture 4 – User requirements Lecture 4 looks at the way systems begin from a system request It explores the reasons for the request and the influences which give rise to it. It then discusses the preliminary investigation stage of the SDLC

15. info1409 2006/7 DMU15 Six of the main reasons for Systems requests P51 Shelley et al

16. info1409 2006/7 DMU16 Systems requests can be the result of both internal and external factors Page 51 Shelley et al

17. info1409 2006/7 DMU17 Lecture 5 - feasibility Lecture 5 looks at Feasibility It explains the different types of feasibility and the reasons for feasibility studies. The following slide illustrates this:

18. info1409 2006/7 DMU18 We will examine each of these in turn in the following slides

19. info1409 2006/7 DMU19 Lecture 6 –the systems analyst Lecture 6 looks at the work of the systems Analyst It explains the necessary skills and activities that a systems analyst needs to use. It looks at information gathering techniques used in analysis.

20. info1409 2006/7 DMU20 Activities Step 2 : Define the Project Scope and Constraints Determining the project scope means defining the specific boundaries or extent of the project Some analysts find it helpful to determine the scope by creating a list for example: MUST DO SHOULD DO COULD DO WON’T DO

21. info1409 2006/7 DMU21 Step 3 -Perform Fact finding Fact finding involves various techniques and may consume several hours, days or weeks Fact finding involves the following: examining organisational charts, conducting interviews, reviewing documentation, observing operations, and conduct a user survey.

22. info1409 2006/7 DMU22 An interview is the primary method of obtaining information (shelley et al p69)

23. info1409 2006/7 DMU23 Lecture 7 –Requirements modelling Lecture 7 looks at modelling the system to the requirements of the organisation and the user. It introduces JAD and RAD and OO methodologies.

24. info1409 2006/7 DMU24 (1) Systems Analysis Phase 1 – Requirements modeling Requirements modelling begins the process

25. info1409 2006/7 DMU25 (2) Joint Application Development Joint application development (JAD) is a popular fact finding technique that brings users into the development process as active participants. P93 Shelley et al Users have a vital stake in the information system and so should participate fully in the development process

26. info1409 2006/7 DMU26 The four phases of the RAD model Notice the continuous interaction between user design and construction

27. info1409 2006/7 DMU27 Object Oriented methods This module will expand our understanding of O.O methodology. Lecture 8 will focus on how CASE tools and Unified Modelling language are part of object oriented analysis concepts.

28. info1409 2006/7 DMU28 Lecture 8 - CASE,UML and OO Lecture 8 discusses the use of CASE tools It explains how Unified modelling language is used in Object Oriented methodology.

29. info1409 2006/7 DMU29 Definition of a CASE environment by Carnegie Mellon From Shelley et al

30. info1409 2006/7 DMU30 Use Case Diagrams During requirements modelling analysts and users work together to model the system functions A Use Case diagram visually represents the interaction between Users and the Information system Use Case diagrams can be drawn freehand, or using Case tools.

31. info1409 2006/7 DMU31 In this diagram the Actor is a customer and the Use Case is a credit validation performed by the system.

32. info1409 2006/7 DMU32 Lecture 9 – Events and Use Case diagrams Lecture 9 gives advice on identifying and recording the Events that happen in the business process It gives examples and hints on translating the Events into Use Case diagrams.

33. info1409 2006/7 DMU33 Events Table: hotel booking EventTriggerSourceUse Case Respons e Destination Customer makes booking customer enquiry customercreate new booking room booking confirm- ation customer and clerk

34. info1409 2006/7 DMU34 Answers 1.Customer contacts the hotel for a free room 2.Clerk checks room availability 3.Customer gives name and address 4.Customer pays deposit 5.Clerk updates system to show room booked 6. Customer rings to order flowers 7. Customer turns up 8. Clerk find room number and gives key 9. Clerk records room as occupied 10. Customer leaves 11. Bill calculated 12. Customer pays bill 13 Clerk records room empty and customer paid. Customer Makes Booking Customer Orders service Customer Checks in Customer Checks out

35. info1409 2006/7 DMU35 Drawing your Use Case Create new booking Booking Clerk Customer Remember this is just a fragment!! Illustration

36. info1409 2006/7 DMU36 Recommended Reading The set text for this module is Systems Analysis & Design Shelley Cashman & Rosenblatt (6 th or 7th Ed) Thomson Course Technology (2006) ISBN 0-619-25510-2 Your reading should also be supplemented by the other references listed at the end of lectures.