1. Successfully Implementing Information Systems
Systems Analysis and Design

2. Learning Objectives
Comprehend the implementation of a variety of distributed systems
Design appropriate training programs for users of the new system
Recognize the differences in physical conversion strategies and be able to recommend an appropriate one to a client
Address security, disaster preparedness, and disaster recovery
Understand the importance of evaluating the new system, and be able to recommend a suitable evaluation technique to a client

3. Figure 0 Every systems analyst should understand the methodology and philosophy of Six Sigma

4. Implementation
The process of ensuring that the information system is operational and then allowing users to take over its operation for use and evaluation
Implementation considerations:
Distributing processing
Training users
Converting from the old system
Evaluating the new system
Distributing processing – concerns the movement of computer power to individual users by setting up and shifting computer power and responsibility to groups throughout the business.
Training users – making sure that each user understands any new role that he or she must take on because of the new information system.
Converting from the old system – choosing a conversion strategy.
Evaluating the new system – evaluate the new or modified system.

5. Major Topics Client/server computing Network types Groupware Training
Security
Organizational metaphors
Evaluation

6. Implementing Distributed Systems
Can be conceived of as an application of telecommunications
Includes work stations that can communicate with each other and with data processors
May have different hierarchical architectural configurations of data processors that communicate with each other
The information architecture model that will likely dominate networking in the next few years is that of client/server.

7. Client/Server Technology
The client/server (C/S) model refers to a design model that can be thought of as applications running on a local area network (LAN)
The client is a networked computer that uses small programs to do front-end processing, including communicating with the user
A file server stores the application programs and data for all the clients on the network
A print server is a PC dedicated to receiving and storing files to be printed
If a file server crashes all clients using the applications on the server are affected.
A print server on a LAN is accessible to all workstations.
Web Servers are software, not a combination of software and hardware as print servers and file servers are.

8. Advantages and Disadvantages of C/S Model
Advantage - greater computer power and greater opportunity to customize applications
Disadvantage - more expensive and applications must be written as two separate software components each running on separate machines
Although lower processing costs are cited as a benefit of the C?S model, there is very little actual data available to prove it.
There are well-documented high start-up or switch-over costs associated with a movement to a C/S architecture.

9. Figure 1 A client/server system configuration

10. Network Types Wide area network (WAN) Local area network (LAN)
Wide-area network (WAN) – serve users over several miles or across entire continents.
Local area network (LAN) – standard for linking local computers or terminals within a department, building, or several buildings of an organization.

11. Wireless Local Area Network (WLAN)
Called Wi-Fi or , wireless fidelity
Can include encryption wired equivalent privacy (WEP) for security purposes
Comparatively cheap to set up
Serve as a flexible technology for supporting work groups
refers to a family of specifications developed by the IEEE for wireless LAN technology.
Hot spots – Wi-Fi networks that are being made available in certain high-internet traffic locations.

12. Wireless Local Area Network (WLAN) (Continued)
Concerns
Security
Signal integrity
WEP has many flaws, but used in conjunction with traditional LAN security measures is thought to be adequate for many home and business purposes
Wi-Fi networks are prone to interference from systems operating nearby in the same frequency spectrum.

13. WiMax Worldwide Interoperability for Microwave Access
Also known as “Mobile WiMax”
Greater wireless access range (30 miles)
One of the current drawbacks is that if the user is trying to get on the Web in an area with a weak signal for cell phones, the Web access will not work either.

14. Bluetooth
Suitable for personal networks and can include computers, printers, handheld devices, phones, keyboards, mice and household appliances

15. Types of Distributed Systems Networks
Hierarchical
Star
Ring
Bus
These are the four main types of distributed systems networks. Each requires different hardware and software and has different capabilities.

16. Hierarchical The host controls all other nodes
Computers on the same level do not communicate with each other
With this arrangement, large-scale computing problems are handled by the mainframe, and lesser computing demands are handles on the correct level by either minicomputers or PC’s.

17. Star The central node communicates with the lesser nodes
The lesser nodes cannot directly communicate with each other
A need for PC’s to communicate with one another would be met by one PC sending data to the central node, which in turn would relay the data to a second PC.

18. Ring There is no central computer
All the nodes are of equal computing power
Each node communicates directly with its neighbour
With the use of a ring network, all PC’s can communicate directly with one another, passing along all the messages they read to their correct destinations on the ring.

19. Bus Work well in close quarters
A single central cable is used to connect all the devices
The single central cable serves as the only communication path
A bus configuration allows a great deal of change by permitting users to add or remove devices quite easily.

20. Network Modelling
Draw a network decomposition diagram to provide an overview of the system
Draw a hub connectivity diagram
Explode the hub connectivity diagram to show the various workstations and how they are connected
A top-down approach is taken

21. Figure 2 Use special symbols when drawing network decomposition and hub connectivity diagrams

22. Figure 3 A network decomposition diagram for World’s Trend example
Start by drawing a circle at the top.
Draw a number of circles on the level below which represent hubs for different divisions, centres etc.
Show the workstations connected to each hub.

23. Figure 4 A hub connectivity diagram for World’s Trend
Shows how the major hubs are connected.
Start by drawing all the hubs. Then experiment to see which links are necessary. Once that is done, redraw the diagram so it is attractive and communicates well to users.

24. Figure 5 A workstation connectivity diagram for World’s Trend
The purpose of network modeling is to show the connectivity of workstations in some detail.

25. Groupware
Software that supports people working together in an organization
Can help group members to schedule and attend meetings, share data, create and analyze documents, communicate in unstructured ways, hold group conferences, do image management, manage and monitor workflow
Groupware takes advantage of the power available from networked PC’s in LAN’s or WANs, or the Web.

26. Figure 8 There are five main advantages to creating distributed systems
Allow the storage of data where they are not in the way of any online real-time transactions:
response time on inquiries might be improved if not all records need to be searched before a response is made.
Not all data are needed by all users all the time, so they can be stored in less-expensive media at a different site and only accessed when needed.
Can lower equipment costs – some capabilities such as processing and storage can be shared.
Flexibility in the choice of manufacturer – this also helps reduce cost.
Initially less expensive than large systems – because it is feasible to plan for expansion without actually having to buy hardware at the time the system is implemented.

27. Figure 9 There are four main disadvantages to creating distributed systems
Reliability – if there are too many problems with system reliability, the system will be abandoned.
Security – increases with widespread access.

28. Training Who to train People who train users Training objectives
Training methods
Training sites
Training materials
Training strategies are determined by who is being trained and who will train them.

29. Who to Train
All people who will have primary or secondary use of the system
Ensure that users of different skill levels and job interests are separated
It is trouble to include novices in the same training sessions as experts – novices are quickly lost and experts are rapidly bored with basics

30. People Who Train Users Vendors Systems analysts External paid trainers
In-house trainers
Other system users
Vendors – often provide offsite one or two day training sessions on their equipment.
Systems analysts – know the organization so can often provide good training.
External paid trainers – may have broad experience in teaching people how to use a variety of computers.
In-house trainers – usually familiar with the skills and learning preferences of personnel and can tailor materials to their needs.
Other system users – let the trainer train a group of users who then act as trainers.

31. Figure 10 Appropriate training objectives, methods, sites, and materials are contingent on many factors
Four major guidelines:
establishing measurable objectives
using appropriate training methods
selecting suitable training sites
employing understandable training materials
Training objectives – let trainees know what is expected of them and allow for evaluation of training when it is complete.
Training materials – users jobs determine what they need to know, and their personalities, experience, and backgrounds determine how they learn best.
Training sites – onsite vs. offsite
Training materials – must be clearly written for the correct audience with a minimum of jargon. Should also be well indexed and available to everyone who needs them.

32. Conversion Strategies
Direct changeover
Parallel conversion
Gradual or Phased conversion
Modular prototype conversion
Distributed conversion
There is no single best way to proceed with conversion.

33. Figure 11 Five conversion strategies for information systems

34. Direct Changeover Advantage Disadvantage
Users have no possibility of using the old system rather than the new one
Disadvantage
Long delays might ensue if errors occur
Users resent being forced into using an unfamiliar system without recourse
No adequate way to compare new results to old

35. Parallel Conversion Advantage Disadvantage
Can check new data against old data
Feeling of security to users
Disadvantage
Cost of running two systems
Doubling employees’ workloads
Faced with a choice, employees may pick old system

36. Gradual Conversion Advantage Disadvantage
Allows users to get involved with the system gradually
Disadvantage
Taking too long to get the new system in place
Inappropriateness for conversion of small, uncomplicated systems

37. Modular Prototype Conversion
Advantage
Each module is thoroughly tested before being used
Users are familiar with each module as it becomes operational
Disadvantage
Prototyping is often not feasible
Special attention must be paid to interfaces

38. Distributed Conversion
Advantage
Problems can be detected and contained
Disadvantage
Even when one conversion is successful, each site will have its own peculiarities to work through
No particular conversion approach is equally suitable for every system implementation.

39. Security Concerns Physical security Logical security
Behavioural security
As more people in the organization gain greater computer power, gain access to the Web, or connect to intranets and extranets, security becomes increasingly difficult and complex.

40. Security Concerns (Continued)
Physical security is securing the computer facility, its equipment, and software through physical means
Logical security refers to logical controls in the software itself
Behavioural security is building and enforcing procedures to prevent the misusing of computer hardware and software
Physical security – machine-readable badges, human sign-in/sign-out system, closed circuit television cameras to monitor computer areas, backing up data frequently and storing backups in a fireproof, waterproof area.
Logical security – passwords, firewall.
Behavioral security – employees should clearly understand what is expected of them, what is prohibited, and the extend of their rights and responsibilities.

41. Special Security Considerations for Ecommerce
Virus protection software
filtering products
URL filtering products
Firewalls, gateways, and virtual private networks
Intrusion detection products

42. Special Security Considerations for Ecommerce (Continued)
Vulnerability management products
Security technologies such as secure socket layering (SSL) for authentication
Encryption technologies
Public key infrastructure (PKI) use and obtaining a digital certificate

43. Privacy Considerations for Ecommerce
Start with a corporate policy on privacy
Only ask for information required to complete the transaction
Make it optional for customers to fill out personal information on the Web site
Start with a corporate policy on privacy – make sure it is prominently displayed.
Make it optional for customers to fill out personal information on the Web site – always give customers an opportunity to maintain the confidentiality of their personal data by not responding.

44. Privacy Considerations for Ecommerce (Continued)
Use sources that allow you to obtain anonymous information about classes of customers
Be ethical
Be ethical – screen scraping and cookie grabbing are clear violations of privacy, and may be illegal as well.
A coordinated policy of security and privacy is essential. It is essential to establish these policies and adhere to them when implementing an ecommerce application.

45. Disaster Recovery Planning
Identify teams responsible for managing a crisis
Eliminate single points of failure
Determine data replication technologies that match the organization’s timetable
Create detailed relocation and transportation plans
Disasters might be natural or man-made:
power outage
hurricane or earthquake
9/11
Disaster preparedness suggests what a company should do if it encounters a crisis.
Disaster recover looks at how a business can continue in the aftermath of a disaster and how it can restore essential systems within the IT infrastructure.

46. Disaster Recovery Planning (Continued)
Provide recovery solutions that include an off-site location
Ensure the physical and psychological well-being of employees and others

47. Identify Who Is Responsible
Whether business operations will continue
How to support communications
Where people will be sent if the business is uninhabitable
Where personnel will go in an emergency
Seeing to the personal and psychological needs
Restoring the main computing and working environments

48. Single Points of Failure and Data Replication Technologies
Redundancy of data provides the key for servers running Web applications
SNAs and data mirroring
Storage area networks (SNAs)
Data mirroring – synchronous remote replication

49. Relocation and Transportation Plans
Send employees home
Remain on site
Relocate to a recovery facility
A one-page memo should be sent to everyone that contains evacuation routes and employee assembly points.

50. Communication Channels
Emergency information Web page
Emergency hotline
Emergency response agencies
Must be able to communicate in the event of failure.

51. Recovery Solutions and Support for the Well-Being of Employees
Recovery involves an off-site location and converting paper documents to digital formats
Well-being of employees might include providing water or safety kits
One way to learn what should comprise a personal workspace disaster supplies kit is to go to The American Red Cross Web site (

52. Other Conversion Considerations
Ordering equipment
Ordering any external materials supplied to the information system
Appointing a manager to supervise the preparation of the installation site
Planning, scheduling, and supervising programmers and data entry personnel
Ordering equipment – up to three months ahead of planned conversion.
Ordering any external materials supplied to the information system - toner cartridges, paper, preprinted forms and magnetic media.
Many of the project management techniques; Gantt charts, PERT, successfully communicating with team members are useful for planning and controlling implementation.

53. Figure 12 Organizational metaphors may contribute to the success or failure of an information system
Research has suggested that the success or failure of a system may be related to the metaphors used by organizational members.

54. Evaluation Techniques
Cost-benefit analysis
Revised decision evaluation approach
User involvement evaluations
The information system utility approach

55. Information System Utility Approach
Possession
Form
Place
Time
Actualization
Goal

56. Information System Utility Approach (Continued)
Possession utility answers the question of who should receive output
Goal utility answers the why of information systems by asking whether the output has value in helping the organization achieve its objectives
Place utility answers the question of where information is distributed

57. Information System Utility Approach (Continued)
Form utility answers the question of what kind of output is distributed to the decision maker
Time utility answers the question of when information is delivered
Actualization utility involves how the information is introduced and used by the decision maker

58. Web Site Evaluation Know how often the Web site is visited
Learn details about specific pages on the site
Find out more about the Web site’s visitors

59. Web Site Evaluation (Continued)
Discover if visitors can properly fill out the forms you designed
Find out who is referring Web site visitors to the client’s site
Determine what browsers visitors are using
Find out if the client’s Web site visitors are interested in advertising

60. Summary Implementation Distributed systems
Client/server
Training users and personnel
Conversion
Direct changeover
Parallel
Phased
Gradual
Modular prototype

61. Summary (Continued) Security Organizational metaphors Evaluation
Physical
Logical
Behavioural
Organizational metaphors
Evaluation