SAD

1. SAD

2. Systems Analysis and Design

3. We will be looking at: • Feasibility study • Analysis and design • Changeover • Maintenance • Human-Computer Interfaces • Documentation

4. This will take us up to ½ Term • There will be a test before ½ Term • An essay will be set over ½ Term

5. Feasibility Study • Processes Carried Out • Cost-effective • Agreed time-scale • Agreed budget • Money – Time – Human Resources

6. Feasibility Study • Preliminary investigationcarried out by a systems analyst • Should we build a new system? • What are the alternatives?

7. Feasibility Study • Requirements analysis - what the new system needs to do.

8. Feasibility Study • Technical report - Does the technology for the new system exist? Would it be difficult to build? to use?

9. Feasibility Study • Schedule report - Can the new system be developed in the time scale available?

10. Feasibility Study • Cost-effective report  - Development costs and running costs need to be balanced against benefits such as reduced costs, better customer service etc Would the new system generate more money than it would cost to create it?

11. Feasibility Study • Budget report - Can the new system be developed within the agreed budget?

12. Feasibility Study • Requirements analysis - what the new system needs to do. • Technical report - Does the technology for the new system exist? Would it be difficult to build? to use? • Schedule report - Can the new system be developed in the time scale available? • Cost-effective report  - Development costs and running costs need to be balanced against benefits such as reduced costs, better customer service etc Would the new system generate more money than it would cost to create it? • Budget report - Can the new system be developed within the agreed budget?

13. Task 1 • http://www.about-electronics.eu/2010/10/01/tomtom-aims-to-cut-journey-times-by-5/

14. Feasibility Study • Once this is done, the go ahead is given for the project (or not). • It is gut feeling, without looking too much into the design • Takes a very experienced person to do this.

15. Task 2

16. Analysis and Design • Investigation: interviews, observation, document inspection, questionnaires. • Data that needs to be held… • Capturing input data and of presenting output data. • Design forms and reports. • suitable software and hardward components to produce an appropriate system configuration. • Team working vs Individual working • Data Flow Diagrams

17. Investigation • questionnaires • to staff and management; • fast method of getting information as many questionnaires can be handed out at the same time. • questions have to be simple • http://www.youtube.com/watch?v=2yhN1IDLQjo

18. Investigation • interviewing of staff and management; more detailed questions can be asked. • questions can be asked based on responses to previous questions • Long time to complete

19. Investigation • observation of procedures (invoicing, accounting etc) • watching people at their workplace can provide a lot of useful information about how a system works and what the problems are. • Takes a lot of time...

20. Investigation • studying of documents; • documents may include user manuals/guidelines • Codes of Conduct • paper files • invoices • receipts - even notices on the wall!

21. Analysis Task

22. System Design • What needs to be and how... • Every aspect of the system is planned in detail

23. What data needs to be held? • Data What data needs to be stored? • How will it be stored? Database design?

24. Data Flow Diagrams

25. DFD’s • Do not draw data flow lines directly between data stores and external entities. There should be a process box between them to show the operation performed. • Most processes will have input data and output data...so state what they are. • Label all the data flow lines so that it is clear what data is being transferred.

26. DFD’s

27. Data Flow Task

28. DFD Task 1 + 2 • Have a go at these DFD’s

29. Capture and output of Data • How is the data collected? • Automatic? Eg bar codes; OMR etc • Design of new data capture forms • How is it outputted? • Receipts? • Reports? • Forms? • Websites?

30. Designing Forms • Bad Form designs • Got to be easy to use • Helpful • Simple • Quick

31. Hardware + Software • What kinds of hardware are needed? • Tills, mice, scanners (barcode), projectors, internet, printer (what kind) • What software is needed? • Operating system, programs, languages, readers,

32. Team working? • Listen to other people's ideas. • share your ideas with others. • help other members of the team. • interact with others - ask questions and generally communicate • respect other people's ideas.

33. Team working? • Can speed up construction time • Share different skills • Need a good manager • Can take up more time managing than producing • Teams might not “get on”

34. Team Working • Virtual Teams • Over the internet • Location free teams • Issues • Different time zones • Monitor productivity?

35. Changeover • Direct • Pilot • Phased • Parallel

36. Changeover • Direct - also known as ‘big bang’, when the changeover is sudden and complete

37. Changeover • Parallel – both systems run at the same time for a while; this is beneficial because, in the event of a problem with the new system, the old system is still available for use

38. Changeover • Phased – elements of the new system are introduced one-at-a-time

39. Changeover • Pilot – the user may be a large company with many departments. • In this type of changeover, a single department would change directly to the new system, and then the rest of the organisation would follow later.

40. Changeover Task

41. Maintenance • Perfective • Adaptive • Corrective maintenance

42. Maintenance • Perfective maintenance – making the system easier to use or adding new features; in short, making the system as good as it can be for its particular purpose

43. Maintenance • Adaptive maintenance – making changes to the system as the needs of the customer change; • an example of this was the millennium bug, where systems across the world had to be changed from a two-digit to a four-digit date format (dd/mm/yy to dd/mm/yyyy)

44. Maintenance • Corrective maintenance – solving problems that occurred during the creation of the new system that were not discovered at the time; ironing out bugs

45. End of Part 1 • Summary • Feasibility study • Analysis and design • Changeover • Maintenance

46. Part 2 • Documentation needed • Looking at HCI

47. Documentation • User documentation • Maintenance documentation. • Annotated listings, algorithms and data dictionaries. • Used by either technical users or end users.

48. Technical Manual • systems specifications- description of systems- data flow diagrams (or similar)

49. Technical Manual • algorithm (program) specifications- algorithm flowcharts (or pseudocode)- program listing- lists of variables used- data dictionary (structure of databases)- With good technical documentation an analyst/programmer should be able to create the system from scratch.

50. User Manual • - software installation procedures- details for starting the program- details for setting security (passwords etc)- details of discs/tapes required- clerical procedures- data preparation (batching / hash totals etc)- how to enter data(which fields; codes used; how to enter dates etc)- details and samples of reports which may be printed- backup procedures to be followed- recovery procedures in the event of hardware failure