Chapter 9 system maintenance
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CHAPTER 9 System maintenance. 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.

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CHAPTER 9 System maintenance

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Chapter 9 system maintenance

CHAPTER 9System maintenance


Chapter objectives

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


Chapter objectives1

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


Chapter objectives2

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


Introduction

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


Overview

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


User support

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


User support1

User Support

  • Help Desks

    • Often called an information center (IC)

    • Enhance productivity and improve utilization of a company’s information resources


User support2

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


User support3

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


Maintenance tasks

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


Maintenance tasks1

Maintenance Tasks

  • Four types of maintenance task can be identified

  • Corrective maintenance

  • Adaptive maintenance

  • Perfective maintenance

  • Preventative maintenance


Maintenance tasks2

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


Maintenance tasks3

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


Maintenance tasks4

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


Maintenance tasks5

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


Maintenance tasks6

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


Maintenance tasks7

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


Maintenance management

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


Maintenance management1

Maintenance Management

  • The Maintenance Team

    • System administrator

    • Systems analysts

      • Analysis

      • Synthesis

    • Programmers

      • Applications programmer

      • Systems programmer

      • Database programmer

      • Programmer/analyst


Maintenance management2

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


Maintenance management3

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


Maintenance management4

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


Maintenance management5

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


Maintenance management6

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


Maintenance management7

Maintenance Management

  • Version Control

    • Version control

    • Archived

    • Essential part of system documentation

    • Companies can purchase software such as Serena


Maintenance management8

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


System performance management

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


System performance management1

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


System performance management2

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)


System performance management3

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


System performance management4

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


System performance management5

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


System performance management6

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

System Security Overview

  • Security is a vital part of every computer system

  • System Security Concepts

    • CIA triangle

    • Integrity

    • Availability

    • Security policy


System security overview1

System Security Overview

  • Risk Management

    • Absolute security is not a realistic goal

    • Risk identification - exploit

    • Risk assessment - risk

    • Risk control

      • Avoidance, mitigation, transference, acceptance


System security overview2

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


Security levels

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


Security levels1

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)


Security levels2

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


Security levels3

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


Security levels4

Security Levels

  • Network Security

    • Network

    • Network interface

    • Encrypted

    • Encrypting network traffic

      • Unencrypted – plain text

      • Private key encryption

      • Public key encryption (PKE)


Security levels5

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


Security levels6

Security Levels

  • Network Security

    • Private networks

      • Private network

    • Virtual private networks

      • Virtual private network (VPN)

      • Tunnel


Security levels7

Security Levels

  • Network Security

    • Ports and services

      • Port

      • Service

      • Port scans

      • Denial of service (DOS)

      • Distributed denial of service (DDOS)


Security levels8

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)


Security levels9

Security Levels

  • Application Security

    • Services

      • Security hole

    • Hardening

      • Malware

    • Application permissions

      • Administrator – super-user

      • User rights - permissions


Security levels10

Security Levels

  • Application Security

    • Input validation

    • Patches and updates

      • Patches

      • Third-party software

      • Automatic update service

    • Software Logs

      • Log


Security levels11

Security Levels

  • File Security

    • Permissions

      • Read a file

      • Write a file

      • Execute a file

      • Read a directory

      • Write a directory

    • User Groups


Security levels12

Security Levels

  • User Security

    • Privilege escalation attack

    • Identity management

    • Password protection

    • Social engineering

      • Pretexting


Security levels13

Security Levels

  • User Security

    • User resistance

    • New technologies

      • Security token

  • Procedural Security

    • Operational security

    • Dumpster diving

    • Paper shredders


Backup and disaster recovery

Backup and Disaster Recovery

  • 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 recovery1

Backup and Disaster Recovery

  • Backup Policies

    • Backup policy: detailed instructions & procedures

    • Backup media

      • Rotation schedule

      • Offsiting

    • Backup Types

      • Full 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 recovery2

Backup and Disaster Recovery

  • 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 recovery3

Backup and Disaster Recovery

  • Business Continuity Issues

    • Test plan

    • Business continuity plan (BCP)

    • Hot site

    • Data replication

    • Business insurance


System obsolescence

System Obsolescence

  • 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 obsolescence1

System Obsolescence

  • 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 obsolescence2

System Obsolescence

  • 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


Future challenges and opportunities

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


Future challenges and opportunities1

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 for forecasting industry trends


Future challenges and opportunities2

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


Future challenges and opportunities3

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


Future challenges and opportunities4

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

Chapter Summary

  • 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 summary1

Chapter Summary

  • 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 summary2

Chapter Summary

  • 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


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