Chapter 11 Presentation

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Chapter 11 Presentation
Systems Implementation, Operation, and Control
Computer System
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Presentation Outline

1. The Steps of Systems Implementation
2. Planning and Organizing a Systems Project
3. Control Over Nonfinancial Information System
   Resources

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I. The Steps of Systems Implementation
A. Establish Plans and Controls
1. Gantt Charts 2. Simple Network
Diagram
B. Executing Planned Implementation
Activities
C. Follow up and Evaluate the New System
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A. Establish Plans and Controls
Plans should incorporate three major components
1. Breakdown of the project into various
phases.
2. Preparing specific budgets applicable to
each phase
3. Setting up specific time tables applicable
to each phase.
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A1. Gantt Charts
Gantt charts show actual and planned time for
activities. However, they do not show the
relationship between various plan activities.
Planned Time
Evaluate software
Actual Time
Select software
Select computer
Train employees
Test system
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Month
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A2. Simple Network Diagram
A network diagram depicts the order in which
activities must be performed.
Evaluate Software
Contact Vendors
Select Software
Train Employees
Review Budget
Start
Allocate Funds
Contact Vendors
Complete
Implement Computer
Select Computer
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A3. Program Evaluation and Review Technique (PERT)

• The network diagram can be expanded to to include
  estimated times for each of the individual
  activities for the project.
• PERT (also known as Critical Path Method) is used
  to estimate the critical path for a project.
• The critical path is a list of activities that
  are critical to the project in the sense that if
  any one of them is delayed, the entire project
  will be delayed.

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B. Executing Planned Implementation Activities

1. Employee Training
2. Acquiring and Installing New Computer Equipment
3. Detailed Systems Design
4. Writing and Testing Computer Programs
5. System Testing
6. Standards Development
7. Documentation
8. File Conversion

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1. Employee Training

• It is likely that if employees are not adequately
  trained, they will simply ignore the system.
• Management must often decide whether to retrain
  existing employees or hire new personnel.

See retraining existing employees considerations
on p. 396
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2. Acquiring and Installing New Computer Equipment

• Security measure
• considerations include
• Special fire extinguishing
• Video monitoring systems
• Specialized door locks

• Facility considerations include
• Humidity and temperature controls
• False floors for wiring

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3. Detailed Systems Design

• The design specifications for a computer program
  are determined by the design team, not the
  programmer.
• Although the programmers primary function is to
  implement a specific plan, it is important for
  the programmer to work in conjunction with the
  design team.

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4. Writing and Testing Computer Programs

• Programmers write programs in accordance with
  design specifications.
• Smaller installations may use prepackaged
  computer programs.
• Testing should involve trying to do everything
  possible to find something wrong with the
  program.

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5. System Testing

• Direct Approach switching to the new system and
  abandoning the old system at a fixed point in
  time (cutover point).
• Parallel Operation run all transactions on both
  old and new systems simultaneously, and compare
  results. Safe but expensive.
• Modular conversion phasing in a new system in
  segments. Can significantly extend testing
  period.

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6. Standards Development

• The computer system should follow certain
  standards to ensure proper functioning and
  compatibility.
• It is important that the individual modules of a
  system interface properly with other system
  components.

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7. Documentation
Documentation serves many purposes including

• Training new employees
• Providing programmers and analysts with useful
  information for future program evaluation and
  modification activities.
• Providing auditors with useful information for
  evaluating internal controls.
• Assisting in assuring that system design
  specifications are met.

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8. File Conversion

• In many cases, files maintained manually must be
  converted to computer format.
• Conversion from manual to computer formats can
  result in numerous errors. Therefore, much of
  the data must be screened after it is entered.

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C. Evaluating the New System
Follow-up is necessary to ensure that the system
is functioning as planned. Approaches to
follow-up and evaluation include Observation Ques
tionnaires Performance Measures Benchmarks
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II. Planning and Organizing a Systems Project

1. Project Selection
2. The Project Team
3. Factoring a Project into Phases and Tasks
4. Time Estimates
5. Project Accounting

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A. Project Selection

• When resources are limited, funding should be
  allocated to projects yielding the greatest
  benefit to the organization.
• The selection of projects by the steering
  committee helps to ensure user participation.

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B. The Project Team

• An application project team includes both
  technical people and users.
• The leader may be from either group depending on
  the situation.
• Project leader has direct responsibility to the
  steering committee for progress and completion.
  Also, maintains communication with principal user
  department manager.

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C. Factoring a Project into Phases and Tasks

• The objective of project breakdown is to
  facilitate assignment and control of labor and
  other project resources.

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D. Time Estimates

• Guesstimates often work well at the beginning of
  a project since there is so much uncertainty.
• Work measurement can be used to refine time
  estimates (See Fig. 11.7 on p. 402)
• Estimates should be revised frequently since they
  can be improved as the project progresses toward
  to area to be completed.

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E. Project Accounting

• A project accounting system is a cost accounting
  system in which costs are assigned to individual
  projects as the projects proceed through their
  development. (See Figure 11.9 on page 405)

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III. Control Over Nonfinancial Information System
Resources

1. Nonfinancial Performance Measures
2. Auditing the Information System
3. Maintaining and Modifying the System

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A. Nonfinancial Performance Measures

1. Hardware Performance
2. Software Performance
3. Personnel Performance

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1. Hardware Performance
What are some measures of hardware performance?

• Measures of system utilization often include
  ratios such as CPU time actually used to that
  available. Utilization statistics can helpful in
  scheduling work and identifying a need for
  expansion.
• Downtime is the percentage of the time that all
  or part of the network is unavailable for use.
• The mean time between failures.
• The mean time to repair the system.

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2. Software Performance
Software performance must be constantly monitored
because of environmental changes that could
affect user satisfaction.

• A very sound overall approach to evaluating
  software performance is to survey system users
  asking a large number of questions regarding
• Ease of use
• Functionality
• User friendliness

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3. Personnel Performance

• Evaluation of the quality of documentation
  written by programmers.
• Data entry evaluation such as keystrokes per hour
  or records entered per hour.
• Effectiveness of systems operators in running
  prescheduled jobs on time.
• Efficiency of repairpersons in terms of number of
  repairs jobs and average length of time required
  for each repair.

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B. Auditing the Information System

• Obtain a detailed description of the internal
  control system. Internal control questionnaires
  are often used for this purpose.
• Perform tests of compliance
• Perform tests of transactions as they flow
  through the system. Extent of testing depends on
  the level to which controls exist and are in
  effective operation. Better controls could mean
  less transaction testing.

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C. Maintaining and Modifying the System

• All modifications to the systems software and
  data schema should be formally reviewed and
  approved.
• Programmers should not have access to the
  operational copy of software being modified.
• Programmers should only modify a non-operational
  copy of the original software. Once completed,
  the modified software should be carefully
  reviewed and then installed by an independent
  person.
• All modifications should be carefully documented.

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Summary

• The Steps of Systems Implementation
• Establish Plans and Controls
• Execute Activities
• Follow Up and Evaluate New System
• Planning and Organizing a Systems Project
• Selection of Projects
• Organization of Project Team
• Breakdown of Project Tasks
• Project Accounting
• Control Over Nonfinancial Information System
  Resources
• Performance measures for hardware, software, and
  personnel
• Auditing the Information System
• Maintaining and Modifying the System