CHAPTER 9 SYSTEM MAINTENANCE Chapter Objectives 2 Explain

CHAPTER 9 SYSTEM MAINTENANCE

Chapter Objectives 2 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

Chapter Objectives 3 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

Chapter Objectives 4 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

Introduction 5 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

Overview 6 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

User Support 7 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

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

User Support 9 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

User Support 10 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

Maintenance Tasks 11 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

Maintenance Tasks 12 Four types of maintenance task can be identified Corrective maintenance Adaptive maintenance Perfective maintenance Preventive maintenance

Maintenance Tasks 13 [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

Maintenance Tasks 14 [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

Maintenance Tasks 15 [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

Maintenance Tasks 16 [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

Maintenance Tasks 17 [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

Maintenance Tasks 18 [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

Maintenance Management 19 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

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

Maintenance Management 21 The Maintenance Team Organizational IT issues 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

Maintenance Management 22 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

Maintenance Management 23 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

Maintenance Management 24 Configuration Management 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

Maintenance Management 25 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

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

Maintenance Management 27 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 Testing, Product baseline: design phase verification of sys. req. & features 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

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

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

System Security Overview 37 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

Security Levels 38 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

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

Security Levels 40 Physical Security Notebook Select computers 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

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

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

Security Levels 43 Network Security Wireless Wired networks Equivalent Privacy (WEP) Wi-Fi Protected Access (WPA) WPA 2 IEEE 802. 11 i WPA 2 is compatible with WPA, so companies easily can migrate to the new security standard

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

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

Security Levels 46 Network Security 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)

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

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

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

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

Security Levels 51 User Security User resistance New technologies Security token Procedural Security Operational security Dumpster diving Paper shredders

Backup and Disaster Recovery 52 Backup: copying data regularly Recovery: restore data & restarting the sys. after an interruption Disaster recovery plan: backup & recovery plan Backup and disaster recovery issues usually are intertwined

Backup and Disaster Recovery 53 Backup Policies Backup policy: detailed instructions & procedures Backup media Rotation schedule Offsiting Backup Full Types backup: All files that match your selection are included into the backup Differential backup: Only those files will be included which have been changed since the last FULL backup

Backup and Disaster Recovery 54 Backup Policies Backup Types Incremental backup: Only those files will be included which have been changed since the last backup Continuous backup: automatically saved of every changed made RAID (Redundant array of independent disks) Fault tolerant Retention periods: keep the backup for a certain period of time

Backup and Disaster Recovery 55 Business Continuity Issues Test plan Business continuity plan (BCP) Hot site Data replication Business insurance

System Obsolescence 56 At some point every system becomes obsolete Signs: The system’s maintenance history indicates that adaptive and corrective maintenance is increasing steadily Operational costs or execution times are increasing rapidly, and routine perfective maintenance does not reverse or slow the trend

System Obsolescence 57 Signs: A software package is available that provides the same or additional services faster, better, and less expensively than the current system New technology offers a way to perform the same or additional functions more efficiently Maintenance changes or additions are difficult and expensive to perform

System Obsolescence 58 Signs: Users request significant new features to support business requirements Systems operation and support continues until a replacement system is installed At some point in a system’s operational life, maintenance costs start to increase, users begin to ask for more features and capability, new systems requests are submitted, and the SDLC begins again

59 Future Challenges and Opportunities The only thing that is certain about the future is continuous change Change itself is neither good nor bad — the real issue is how people and companies deal with the challenges and opportunities that are bound to occur

60 Future Challenges and Opportunities Predictions The highest priorities will be the safety and security of corporate operations, environmental concerns, and bottom-line TCO Gartner, Inc. is a leading IT consulting firm that is famous forecasting industry trends

61 Future Challenges and Opportunities Predictions Gartner also predicted that by 2011, large enterprises will require suppliers to certify their green credentials and sourcing policies Author Randall Stross notes that the enormous amount of energy needed to drive cloud computing, including Google’s servers, has raised serious environmental concerns

62 Future Challenges and Opportunities Strategic planning for IT professionals Working backwards from your long-term goals, you can develop intermediate mile stones and begin to manage your career just as you would manage an IT project Planning a career is not unlike planting a tree that takes several years to reach a certain height

63 Future Challenges and Opportunities IT Credentials and Certification Credentials Certification In addition to Microsoft, many other IT industry leaders offer certification, including Cisco, Novell, Oracle, and Sun Microsystems

Chapter Summary 64 Systems support and security covers the entire period from the implementation of an information system until the system no longer is used A systems analyst’s primary involvement with an operational system is to manage and solve user support requests A maintenance team consists of one or more systems analysts and programmers

Chapter Summary 65 Systems analysts need the same talents and abilities for maintenance work as they use when developing a new system Configuration management is necessary to handle maintenance requests Security is a vital part of every computer system Risk management creates a workable security policy

Chapter Summary 66 All information systems eventually become obsolete An IT professional should have a strategic career plan that includes long-term goals and intermediate milestones An important element of a personal strategic plan is the acquisition of IT credentials and certifications that document specific knowledge and skills