Chapter 11 Presentation

Systems Implementation, Operation, and Control

Computer

System

Presentation Outline

I. The Steps of Systems Implementation

II. Planning and Organizing a Systems Project

III. Control Over Nonfinancial Information System Resources

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

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.

A1. Gantt Charts

Gantt charts show actual and planned time for activities. However, they do not show the relationship

between various plan activities.

Evaluate software

Select software

Select computer

Train employees

Test system

Planned TimeActual Time

Month

1 2 3 4 5 6 7

A2. Simple Network Diagram

A network diagram depicts the order in which activities must be performed.

Contact Vendors

Review Budget

Evaluate Software

Allocate Funds

Select Software Train

Employees

Contact Vendors

Select Computer

Implement Computer

Complete

Start

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.

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

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

2. Acquiring and Installing New Computer Equipment

Facility considerations include:

Humidity and temperature controls

False floors for wiring

Security measure considerations include:

Special fire extinguishing Video monitoring systems

Specialized door locks

3. Detailed Systems Design

The design specifications for a computer program are determined by the design

team, not the programmer. Although the

programmer’s primary function is to implement a

specific plan, it is important for the

programmer to work in conjunction with the design

team.

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.

5. System TestingDirect 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.

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.

7. Documentation

Training new employeesProviding 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.

Documentation serves many purposes including:

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.

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

Questionnaires

Performance Measures

Benchmarks

II. Planning and Organizing a Systems Project

A. Project Selection

B. The Project Team

C. Factoring a Project into Phases and Tasks

D. Time Estimates

E. Project Accounting

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.

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.

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.

New System

Analysis ImplementDesign

ReportInterview Architect. Detail Train Install

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.

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)

III. Control Over Nonfinancial Information System Resources

A. Nonfinancial Performance Measures

B. Auditing the Information System

C. Maintaining and Modifying the System

A. Nonfinancial Performance Measures

1. Hardware Performance

2. Software Performance

3. Personnel Performance

1. 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.

What are some measures of hardware

performance?

2. Software Performance

A very sound overall approach to evaluating software

performance is to survey system users asking a large

number of questions regarding:Ease of use

FunctionalityUser friendliness

Software performance must be constantly monitored because of

environmental changes that could affect user satisfaction.

3. Personnel PerformanceEvaluation 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.

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.

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.

SummaryThe Steps of Systems Implementation

Establish Plans and ControlsExecute 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