CHAPTER 9 System maintenance

1. CHAPTER 9System maintenance

2. Chapter Objectives • Explain the systems support and security phase • Describe user support activities, including user training and help desks • Define the four types of maintenance • Explain various techniques for managing systems maintenance and support

3. Chapter Objectives • Describe techniques for measuring, managing, and planning system performance • Explain risk management concepts • Assess system security at six levels: physical security, network security, application security, file security, user security, and procedural security

4. Chapter Objectives • Describe backup and disaster recovery • List factors indicating that a system has reached the end of its useful life • Assess future challenges and opportunities for IT professionals • Develop a strategic plan for career advancement and strong IT credentials

5. Introduction • Managing systems support and security involves three main concerns: user expectations, system performance, and security requirements • Successful, robust systems often need the most support • In most organizations, more than half of all IT department effort goes into supporting existing systems

6. Overview • The systems operation, support, and security phase begins when a system becomes operational and continues until the system reaches the end of its useful life • After delivering the system, the IT team focuses on support and maintenance tasks

7. User Support • User Training • Additionally, new employees must be trained on the company’s information systems • User training package • Training users about system changes is similar to initial training • Objective is to show users how the system can help them perform their jobs

8. User Support • Help Desks • Often called an information center (IC) • Enhance productivity and improve utilization of a company’s information resources

9. User Support • Help Desk • Might have to perform the following tasks: • Show a user how to create a data query or report that displays specific business information • Resolve network access or password problems • Demonstrate an advanced feature of a system or a commercial package • Help a user recover damaged data

10. User Support • Help Desk • In addition to functioning as a valuable link between IT staff and users, the help desk is a central contact point for all IT maintenance activities • Can utilize many types of automated support

11. Maintenance Tasks • The systems operation, support and security phase is an important component of TCO (total cost of ownership) because ongoing maintenance expenses can determine the economic life of a system • Operational costs • Maintenance expenses • Maintenance activities

12. Maintenance Tasks • Four types of maintenance task can be identified • Corrective maintenance • Adaptive maintenance • Perfective maintenance • Preventative maintenance

13. Maintenance Tasks • [1] Corrective Maintenance • Diagnoses and corrects errors in an operational system • Respond to errors in various ways, depending on nature and severity of the problem • In a typical procedure, a user submits a systems request that is evaluated, prioritized and scheduled

14. Maintenance Tasks • [1] Corrective Maintenance • For more serious situations, a user submits a systems request with supporting evidence • Worst-case situation is a system failure • When the system is operational again, the maintenance team determines the cause, analyzes the problem, and designs a permanent solution

15. Maintenance Tasks • [2] Adaptive Maintenance • Adds enhancements to an operational system and makes the system easier to use • The procedure for minor adaptive maintenance is similar to routine corrective maintenance • Can be more difficult than new systems development because the enhancements must work within the constraints of an existing system

16. Maintenance Tasks • [3] Perfective Maintenance • Involves changing an operational system to make it more efficient, reliable and maintainable • Can improve system reliability • Cost-effective during the middle of the system’s operational life

17. Maintenance Tasks • [3] Perfective Maintenance • Software reengineering • Programs that need a large number of maintenance changes usually are good candidates for reengineering • The more a program changes, the more likely it is to become inefficient and difficult to maintain

18. Maintenance Tasks • [4] Preventive Maintenance • Requires analysis of areas where trouble is likely to occur • IT department normally initiates preventative maintenance • Often results in increased user satisfaction, decreased downtime, and reduced TCO • Sometimes does not receive the high priority that it deserves

19. Maintenance Management • Requires effective management, quality assurance and cost control • To achieve these goals, companies use various strategies • In addition, firms use version control and baselines to track system releases and analyze the system’s life cycle

20. Maintenance Management • The Maintenance Team • System administrator • Systems analysts • Analysis • Synthesis • Programmers • Applications programmer • Systems programmer • Database programmer • Programmer/analyst

21. Maintenance Management • The Maintenance Team • Organizational issues • IT managers often divide systems analysts and programmers into two groups: one group performs new system development, and the other group handles maintenance • Many analysts feel that maintenance work is less attractive than developing new systems • One disadvantage of rotation is that it increases overhead costs

22. Maintenance Management • Maintenance Requests • Involve a series of steps • All work must be covered by a specific request • Initial determination • The systems review committee • Task completion • User notification

23. Maintenance Management • Establishing Priorities • In many companies, systems review committee separates maintenance requests from new systems development requests • Some IT managers believe that evaluating all projects together leads to the best possible decisions • Object is to have a procedure that balances new development and necessary maintenance work

24. Maintenance Management • Configuration Management • Configuration management (CM) • Configuration management (CM) is a process for controlling changes in system requirements during the development phases of the SDLC. • As enterprise-wide information systems grow more complex, configuration management becomes critical • Also helps to organize and handle documentation

25. Maintenance Management • Maintenance Releases • Maintenance release methodology: numbering system • Maintenance release • A numbering pattern distinguishes the different released • Reduces the documentation burden • But new features or upgrades are available less often • Service packs

26. Maintenance Management • Version Control • Version control • Archived • Essential part of system documentation • Companies can purchase software such as Serena

27. Maintenance Management • Baselines • Systems analysts use baselines as yardsticks to document features and performance during the systems development process • Functional baseline: beginning of the project • Sys. Req. & design constraints • Allocated baseline: design phase • Testing, verification of sys. req. & features • Product baseline: system operation • Performance results & UAT

28. System Performance Management • Today, companies use complex networks and client/server systems to support business needs • To ensure satisfactory support for business operations, the IT department must manage system faults and interruptions, measure system performance and workload, and anticipate future needs

29. System Performance Management • Fault Management • The more complex the system, the more difficult it can be to analyze symptoms and isolate a cause • The best strategy is to prevent problems by monitoring system performance and workload

30. System Performance Management • Performance and Workload Measurement • Benchmark testing • Metrics • Response time • Bandwidth and throughput • Kbps (kilobits per second) • Mbps (megabits per second) • Gbps (gigabits per second)

31. System Performance Management • Performance and Workload Measurement • Turnaround time • The IT department often measures response time, bandwidth, throughput, and turnaround time to evaluate system performance both before and after changes to the system or business information requirements • Management uses current performance and workload data as input for the capacity planning process

32. System Performance Management • Capacity Planning • What-if analysis • You need detailed information about the number of transactions; the daily, weekly, or monthly transaction patterns; the number of queries; and the number, type, and size of all generated reports

33. System Performance Management • Capacity Planning • Most important, you need an accurate forecast of future business activities • If new business functions or requirements are predicted, you should develop contingency plans based on input from users and management

34. System Performance Management • System Maintenance Tools • Many CASE tools include system evaluation and maintenance features • In addition to CASE tools, you also can use spreadsheet and presentation software to calculate trends, perform what-if analyses, and create attractive charts and graphs to display the results

35. System Security Overview • Security is a vital part of every computer system • System Security Concepts • CIA triangle • Integrity • Availability • Security policy

36. System Security Overview • Risk Management • Absolute security is not a realistic goal • Risk identification - exploit • Risk assessment - risk • Risk control • Avoidance, mitigation, transference, acceptance

37. System Security Overview • Attacker Profiles and Attacks • An attack might be launched by a disgruntled employee, or a hacker who is 10,000 miles away • Attackers break into a system to cause damage, steal information, or gain recognition, among other reasons

38. Security Levels • Must consider six separate but interrelated levels • Physical Security • First level of security concerns the physical environment • Physical access to a computer represents an entry point into the system and must be controlled and protected

39. Security Levels • Physical Security • Operations center security • Biometric scanning systems • Servers and desktop computers • Keystroke logger • Tamper-evident cases • BIOS-level password • Boot-level password • Power-on password • Uninterruptible power supply (UPS)

40. Security Levels • Physical Security • Notebook computers • Select an operating system that allows secure logons and BIOS-level passwords • Mark or engrave the computer’s case • Consider notebook models that have a built-in fingerprint reader • many notebook computers have a Universal Security Slot (USS) • Back up all vital data

41. Security Levels • Physical Security • Notebook computers • Use tracking software • While traveling, try to be alert to potential high-risk situations • Establish stringent password protection policies

42. Security Levels • Network Security • Network • Network interface • Encrypted • Encrypting network traffic • Unencrypted – plain text • Private key encryption • Public key encryption (PKE)

43. Security Levels • Network Security • Wireless networks • Wired Equivalent Privacy (WEP) • Wi-Fi Protected Access (WPA) • WPA2 • IEEE 802.11i • WPA2 is compatible with WPA, so companies easily can migrate to the new security standard

44. Security Levels • Network Security • Private networks • Private network • Virtual private networks • Virtual private network (VPN) • Tunnel

45. Security Levels • Network Security • Ports and services • Port • Service • Port scans • Denial of service (DOS) • Distributed denial of service (DDOS)

46. Security Levels • Network Security • Firewalls • Firewall • Firewalls can be configured to detect and respond to denial-of-service attacks, port scans, and other suspicious activity • Network intrusion detection – network intrusion detection system (NIDS)

47. Security Levels • Application Security • Services • Security hole • Hardening • Malware • Application permissions • Administrator – super-user • User rights - permissions

48. Security Levels • Application Security • Input validation • Patches and updates • Patches • Third-party software • Automatic update service • Software Logs • Log

49. Security Levels • File Security • Permissions • Read a file • Write a file • Execute a file • Read a directory • Write a directory • User Groups

50. Security Levels • User Security • Privilege escalation attack • Identity management • Password protection • Social engineering • Pretexting