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CHAPTER 22
SYSTEMS DESIGN, IMPLEMENTATION, AND OPERATION
Instructor’s Manual
Learning Objectives:
1. Discuss the conceptual systems design process and the
activities in this phase.
3. Discuss the systems implementation and conversion
process and the activities in this phase.
Questions to be addressed in this chapter include:
1. Should her team develop what it considers to be the best approach
to meeting SM’s needs, or should they develop several approaches?
Introduction
Accountants should help keep the project on track by evaluating and
measuring benefits, monitoring costs, and ensuring that the project
stays on schedule.
This chapter discusses the other four steps (see Figure 12-1) in the
systems development life cycle:
2. Physical systems design
4. Operation and maintenance
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Conceptual Systems Design
In the conceptual systems design phase, the developer creates a general
framework for implementing user requirements and solving problems
identified in the analysis phase.
As shown in Figure 22-1, there are three main steps in conceptual
design:
1. Evaluating design alternatives
Evaluate Design Alternatives
There are many ways to design an AIS, so accountants and others
involved in systems design must continually make design decisions.
The design team should identify a variety of design alternatives and
evaluate each with respect to the following standards:
1. How well it meets organizational and system objectives
Table 22-1 presents examples of conceptual and physical design
considerations and their corresponding design alternatives.
Prepare Design Specifications
Once a design alternative has been selected, the project team develops
1. Output. Because the system is designed to meet users’ information
needs, output specifications must be prepared first.
2. Data storage. For Shoppers Mart, decisions included
▪ Which data needs to be stored for the sales report
3. Input. Design considerations for Shoppers Mart include which
sales data to enter, sale location and amount, and where, when,
and how to collect data.
4. Processing procedures and operations. Design considerations for
Shoppers Mart include how to process the input and stored data to
Prepare the Conceptual Systems Design Report
At the end of the conceptual design phase, a conceptual systems design
report is prepared to:
1. Guide physical systems design activities
Multiple Choice 1
In the conceptual design phase of the systems development life cycle,
_____ specifications must be prepared first.
a. input
Multiple Choice 2
Assumptions and unresolved problems are included in the following
report(s):
a. conceptual systems design report
b. physical systems design report
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Physical Systems Design
During the physical systems design phase, the company determines how
the conceptual AIS design is to be implemented.
Output Design
The objective of output design is to determine the nature, format,
content, and timing of printed reports, documents, and screen displays.
Some important output design considerations are summarized in Table 22–
2.
Output usually fits into one of the following four categories:
1. Scheduled reports have a prespecified content and format and
are prepared on a regular basis.
File and Database Design
Table 22-3 summarizes some of the more important file and database
design considerations: 1) medium, 2) processing mode and maintenance
size, and 3) activity level.
Input Design
Considerations for input design are shown in Table 22-4.
Note #1: General considerations include:
1. Preprint as much data as possible.
3. Use bold type, double-thick lines, and shading to highlight
different parts of the form.
4. Use a standard size and one that is consistent with requirements
for filing, binding, or mailing.
Forms Design
Table 22-5 is a useful tool for evaluating existing forms and designing
new ones:
2. Introductory Section Of Form
4. Conclusion Section Of Form
Designing Computer Screens
Computer screens are most effective when these procedures are followed:
1. Organize the screen so data can be entered quickly, accurately,
and completely.
3. Complete the screen from left to right and top to bottom. Group
together logically related data.
4. Design the screen so users can jump from one data entry location
6. Restrict the amount of data on a screen to avoid clutter. Limit
the number of menu options on a single screen.
Program Design
Program development is one of the most time-consuming activities in the
SDLC.
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Programs subdivided into small, well-defined modules are a process
called structured programming.
Following are eight steps for developing software:
Step 1 Determine user needs. Systems analysts consult with users
and agree on software requirements.
Step 1 is performed as a part of the systems analysis phase of
the SDLC.
Step 4 Test the program. Debugging is discovering and eliminating
program errors. After a program is coded, a visual and mental
review, referred to as desk checking, is conducted to discover
programming errors.
FOCUS 22-1 discusses the difficulty of testing software and the
consequences of releasing software with undetected errors.
Most of the tasks in steps 3 and 4 are done during systems design
and are completed during systems implementation.
Step 5 Document the program. Documentation explains how programs
work and is used to help correct and resolve errors.
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include requests for new or revised reports; changes in input,
file content, or values such as tax rates; error detection; and
conversion to new hardware.
Step 8 is part of the operation and maintenance phase.
Procedures Design
Controls Design
The often-heard computer adage “garbage in, garbage out” emphasizes
that improperly controlled input, processing, and database functions
produce information of little value.
Some of the more important control concerns that must be addressed are
summarized in Table 22-6:
1. Validity
3. Accuracy
5. Numerical control
7. Maintainability
9. Audit trail
Physical Systems Design Report
At the end of this phase, the team prepares a physical systems design
report that summarizes what was accomplished and serves as the basis
Multiple Choice 3
The following consideration(s) are involved in the file and database
design.
a. use
b. operations
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c. medium
d. A and C
Multiple Choice 4
“Is additional training necessary?” is a concern to be answered during
_____ design.
a. input
b. output
Multiple Choice 5
_____ development is one of the most time consuming activities in the
SDLC.
a. Input
Multiple Choice 6
__________ is done during systems design and is completed during
systems implementation.
a. Develop a plan
Systems Implementation
Systems implementation is the process of installing hardware and
software and getting the AIS up and running.
Implementation Planning
An implementation plan consists of implementation tasks, expected
completion dates, cost estimates, and the person or persons responsible
for each task.
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One reason that Blue Cross/Blue Shield’s new $200 million system failed
was because there was no organizational restructuring.
Site Preparation
Select and Train Personnel
Employees can be hired from outside the company or transferred
internally.
Boots the Chemists at a London-based international pharmacy developed a
new approach to training.
Store employees that were nervous about the new computer system
were invited to a party where a new POS system had been
installed.
Complete Documentation
Three types of documentation must be prepared for new systems:
1. Development documentation describes the new AIS. It includes:
▪ A system description
2. Operations documentation includes:
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3. User documentation teaches users how to operate the AIS. It
includes a procedures manual and training materials.
Test the System
Inadequate system testing was one reason for the Blue Cross/Blue Shield
system failure described previously.
Following are three common forms of testing:
1. Walk-throughs are step-by-step reviews of procedures or
program logic.
Chemical Bank suffered the consequences of not adequately testing an
upgrade to its ATM system.
Customers in New York who withdrew money found that there
accounts were debited twice.
Systems Conversion
Conversion is the process of changing from the old to the new AIS. This
includes converting hardware, software, data files, and procedures.
Conversion Approaches
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Four conversion approaches are used to change from an old to a new
system:
1. Direct conversion immediately terminates the old AIS when the
new one is introduced.
FOCUS 22-3 discusses the problems at Sunbeam Corp., in part
caused by attempting a direct conversion with no backup
system.
Al Dunlap, a new CEO at Sunbeam Corp., made drastic cost–
cutting moves in which many went too far and ended up
hurting the company.
Al used the direct conversion approach to modernize its
information system. Unfortunately, the new system did not
work. Without any backup system the entire system was down
for months.
Orders were lost and some customers did not receive their
shipments.
2. Parallel conversion operated the old and new systems
simultaneously for a period of time.
3. Phase-in–conversion gradually replaces elements of the old AIS
with the new one.
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4. Pilot conversion implements a system in just one part of the
organization, such as a branch location.
Data Conversion
Data conversion can be time-consuming, tedious, and expensive. The
difficulty and magnitude of the task can be easily underestimated.
Multiple Choice 7
Blue Cross/Blue Shield contracted for a new $_____ million system which
did not work properly. This resulted in $_____ million in overpayments
and a loss of _____ clients.
a. 200; 70; 30,000
b. 100; 60; 35,000
c. 200; 60; 35,000
d. 100; 70; 30,000
Multiple Choice 8
Walk-throughs are conducted by the:
a. development team
Multiple Choice 9
The first step in the data conversion process is:
a. check data for completeness, and any data inaccuracies, and
remove any inconsistencies
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Operation and Maintenance
The final step in the SDLC is to operate and maintain the new system. A
post-implementation review should be conducted on a newly installed AIS
to ensure it meets its planned objectives.
Factors include:
1
Goals and objectives
8
Compatibility
2
Satisfaction
9
Controls and security
3
Benefits
10
Errors
4
Training
5
Reliability
12
Communications
6
Organizational changes
7
Timeliness
14
Documentation
User acceptance of the post-implementation review report is the final
activity in the systems development process.
However, work on the new system is not finished. Studies show that over
the life of a system, only 30 percent of the work takes place during
development. The remaining 70 percent is spent on maintaining the
system.
Multiple Choice 10
Studies have shown that _____ percent of the work takes place during
development and _____ percent is spent maintaining the system.
a. 30; 70
b. 70; 30
c. 65; 35
d. 35; 65