Chapter 13



Chapter 13

Systems Design, Implementation, Maintenance, and Review

|At a Glance |

Instructor’s Manual Table of Contents

□ Chapter Overview

□ Chapter Outline

□ Chapter Principles and Objectives

□ Teacher Notes

□ Quick Quizzes

□ Teaching Tips

□ Further Readings or Resources

□ Discussion Questions

□ Projects to Assign

□ Key Terms

Chapter Overview

The way an information system is designed, implemented, and maintained profoundly affects the daily functioning of an organization. Like investigation and analysis, design, implementation, maintenance, and review strive to achieve organizational goals, such as reduced costs, increased profits, or improved customer service. The goal is to develop a new or modified system to deliver the right information to the right person at the right time.

Chapter Outline

|Lecture Topics |Page # |

|Systems Design |13-4 |

|Systems Implementation |13-5 |

|Systems Maintenance |13-8 |

|Systems Review |13-8 |

Chapter Principles and Objectives

|Principles |Learning Objectives |

| | |

|Designing new systems or modifying existing ones should always be|State the purpose of systems design and discuss the differences |

|aimed at helping an organization achieve its goals. |between logical and physical systems design. |

| |Outline key steps taken during the design phase. |

| |Describe some considerations and diagrams used during |

| |object-oriented design. |

| |Define the term RFP and discuss how this document is used to |

| |drive the acquisition of hardware and software. |

| |Describe the techniques used to make systems selection |

| |evaluations. |

| | |

|The primary emphasis of systems implementation is to make sure |State the purpose of systems implementation and discuss the |

|that the right information is delivered to the right person in |various activities associated with this phase of systems |

|the right format at the right time. |development. |

| |List the advantages and disadvantages of purchasing versus |

| |developing software. |

| |Discuss the software development process and some of the tools |

| |used in this process, including object-oriented program |

| |development tools. |

| | |

|Maintenance and review add to the useful life of a system but can|State the importance of systems and software maintenance and |

|consume large amounts of resources. These activities can benefit |discuss the activities involved. |

|from the same rigorous methods and project management techniques |Outline key steps taken during the design phase |

|applied to systems development. | |

| | |

Teacher Notes

Systems Design

The purpose of Systems design is to answer the question, "How will the information system solve a problem?" The primary result of the systems design phase is a technical design that details system outputs, inputs, and user interfaces; specifies hardware, software, databases, telecommunications, personnel, and procedures; and shows how these components are related. The new system should overcome the shortcomings of the existing one and help the organization achieve its goals.

Systems design is generally comprised of two major components: logical design and physical design.

Logical design describes the functional requirements of a system. That is, it conceptualizes what the system will do to solve the problems identified through earlier analysis. Without this step, the technical details of the system (such as which hardware devices should be acquired) often obscure the best solution. The logical design specifications that are determined and documented include the following:

| Logical design | |

|specification |Output design |

| |Input design |

| |Process design |

| |Procedures design |

| |Telecommunications design |

Physical design specifies the characteristics of the system components necessary to put the logical design into action. In this phase, the characteristics of each of the following components must be specified:

|Physical design | |

|specification |Hardware design |

| |Software design |

| |Database design |

| |Personnel design |

A number of special system characteristics should be considered during both logical and physical design. These include sign-on procedures, interactive processing, interactive dialogue, error prevention and detection, and emergency alternate procedures.

Object Oriented Design

Logical and physical design can be accomplished using either the traditional structured approach or the object-oriented (OO) approach to systems development. Using the OO approach, we design key objects and classes of objects in the new or updated system. The sequence of events that a new or modified system requires is often called a scenario, which can be diagrammed in a sequence diagram.

Emergency Alternate Procedures and Disaster Recovery

Emergency alternative procedures and disaster recovery are important aspects of systems design. Disaster planning is the process of anticipating and providing for disasters. A disaster can be an act of nature (a flood, fire, or earthquake) or a human act (terrorism, error, labor unrest, or erasure of an important file). The primary tools used in disaster planning and recovery are hardware, software, database, telecommunications, and personnel backup.

Systems Controls

Security, fraud, and the invasion of privacy are also important design considerations. Most IS departments establish tight systems controls to maintain data security. Systems controls can help prevent computer misuse, crime, and fraud by employees and others. System controls include input, output, processing, database, telecommunications, and personnel controls.

The Importance of Vendor Support

Whether an individual is purchasing a personal computer or an experienced company is acquiring an expensive mainframe computer, the system could be obtained from one or more vendors. Some of the factors to consider in selecting a vendor are the vendor’s reliability and financial stability, the type of service offered after the sale, the goods and services the vendor offers and keeps in stock, the vendor’s willingness to demonstrate its products, the vendor’s ability to repair hardware, the vendor’s ability to modify its software, the availability of vendor-offered training of IS personnel and system users, and evaluations of the vendor by independent organizations.

Evaluating and Selecting a System Design

The final step in systems design is to evaluate the various alternatives and select the one that will offer the best solution for organizational goals. Normally, evaluation and selection involves both a preliminary and a final evaluation before a design is selected.

Quick Quiz

1. What is the purpose of systems design?

ANSWER: To answer the question, "How will an information system solve this problem?"

2. What procedure consists of identification numbers, passwords, and other safeguards needed for an individual to gain access to computer resources?

ANSWER: Sign-on procedure

3. _____ is a simplified process used to access an application from where it left off?

ANSWER: Restart procedure

4. What term is used to describe rules and procedures that prevent problems before they occur?

ANSWER: Deterrence controls

Systems Implementation

After the information system is designed, a number of tasks must still be completed before the system can be installed and is ready to operate. This process, called systems implementation, includes the following components:

|Components of Systems | |

|Implementation: |Hardware acquisition |

| |Software acquisition or development |

| |User preparation |

| |Hiring and training of personnel |

| |Site and data preparation |

| |Installation |

| |Testing |

| |Start-up |

| |User-acceptance |

To obtain the components for an information system, organizations can purchase, lease, or rent computer hardware and other resources from an IS vendor. It is also possible to purchase used computer equipment. This option is especially attractive to firms that are experiencing an economic slowdown.

Application software can be acquired in two ways: it can be purchased from external developers or developed in-house. This is normally referred to as the make-or-buy decision. Purchasing or leasing externally developed software has a number of advantages, including: lower costs, less risk regarding the features and performance of the package, and ease of installation.

User preparation is the process of readying managers, decision makers, employees, other users, and stakeholders for the new systems. This activity is an important, but often ignored, area of systems implementation.

Depending on the size of the new system, an organization may have to hire and, in some cases, train new IS personnel. An information systems manager, systems analysts, computer programmers, data entry operators, and similar personnel may be needed for the new system.

The location of the new system needs to be prepared in a process called site preparation. For a small system, site preparation can be as simple as rearranging the furniture in an office to make room for a computer. With a larger system, this process is not so easy because it may require special wiring and air-conditioning. If the organization is computerizing its work processes, all manual files must be converted to computer files in a process called data preparation, or data conversion. All permanent data must be placed on a permanent storage device, such as magnetic tape or disk.

Installation is the process of physically placing the computer equipment on the site and making it operational. Although normally the manufacturer is responsible for installing computer equipment, someone from the organization (usually the IS manager) should oversee the process, making sure that all equipment specified in the contract is installed at the proper location. After the system is installed, the manufacturer performs several tests to ensure that the equipment is operating as it should.

Good testing procedures are essential to make sure that the new or modified information system operates as intended. Inadequate testing can result in mistakes and problems. Several forms of testing should be used, including testing each of the individual programs (unit testing), testing the entire system of programs (system testing), testing the application with a large amount of data (volume testing), and testing

all related systems together (integration testing), as well as conducting any tests required by the user (acceptance testing).

Start-up begins with the final tested information system. When start-up is finished, the system is fully operational. Direct conversion (also called plunge or direct cutover) involves stopping the old system and starting the new one on a given date. Direct conversion is usually the least desirable approach because of the potential for problems and errors when the old system is shut off and the new system is turned on at the same time. The phase-in approach is a popular technique preferred by many organizations. In this approach, sometimes called a piecemeal approach, components of the new system are slowly phased in while components of the old one are slowly phased out. Pilot start-up involves running the new system for one group of users rather than all users. Parallel start-up involves running both the old and new systems for a period of time. The output of the new system is compared closely with that of the old system, and any differences are reconciled.

Most mainframe computer manufacturers use a formal user acceptance document. This is a legal document that usually removes or reduces the information systems vendor from liability for problems that occur after the user acceptance document has been signed. Because this document is so important, many companies get legal assistance before they sign the acceptance document.

Quick Quiz

1. What is a term used to describe a group of skilled IS professionals with the task of designing and implementing a set of programs?

ANSWER: Chief programmer team

2. What type of documentation is used by computer operators, or by programmers that need to change a system?

ANSWER: Technical

3. What are the three structured programming constructs?

ANSWER: Sequence, decision, and loop

4. What is the process of physically placing the computer equipment on the site and making it operational?

ANSWER: Installation

Systems Maintenance

Systems maintenance involves checking, changing, and enhancing the system in order to make it more useful in achieving user and organizational goals. Once a program is written, it is likely to need ongoing maintenance and experience has shown that frequent, minor maintenance to a program, if properly done, can prevent major system failures later. Some of the reasons for program maintenance include the following:

|Steps to Ensure | |

|Privacy: |Changes in business processes. |

| |New requests from stakeholders, users, and managers. |

| |Bugs or errors in the program. |

| |Technical and hardware problems. |

| |Corporate mergers and acquisitions. |

| |Government regulations. |

| |Change in operating systems or hardware platforms. |

Quick Quiz

1. Many companies do not announce to users that a(n) _____ upgrade has been made.

ANSWER: slipstream

2. A new _____ is a significant program change that often requires changes in the documentation of the software.

ANSWER: release

3. A(n) _____ is a minor change to correct a problem or make a small enhancement.

ANSWER: patch

Systems Review

Systems review, the final step of systems development, is the process of analyzing systems to make sure that they are operating as intended. This process often compares the performance and benefits of the system as it was designed with the actual performance and benefits of that in operation. Problems and opportunities uncovered during systems review will trigger systems development and begin the process anew.

There are two types of review procedures: event driven and time driven. An event-driven review is triggered by a problem or opportunity such as an error, a corporate merger, or a new market for products. In some cases, companies wait until a large problem or opportunity occurs before a change is made, ignoring minor problems. In contrast, some companies use a continuous improvement approach to systems development. With this approach, an organization makes changes to a system even when small problems or opportunities occur.

A time-driven review is performed after a specified amount of time. With this approach, an existing system is monitored on a schedule. If problems or opportunities are uncovered, a new systems development cycle may be initiated.

Quick Quiz

1. What type of review would be used after a system error occurred?

ANSWER: Event-driven review

2. What is the final step in systems development?

ANSWER: Systems review

3. What type of review is conducted periodically?

ANSWER: Time-driven review

Teaching Tips

• Invite a member of a systems development team into the classroom to discuss a project.

• Invite a programmer into the class to lead a discussion about their job. A chief programmer, who can provide information about system conversion, is a good choice.

• Demonstrate an automatic code generator. Microsoft Access can be used to illustrate the generation of SQL if other packages are not available.

• Show students an example of computer code from an actual process. Identify any business rules that can be found in it.

• Ask students to find articles on software maintenance and review. Ask them to locate a numeric figure that indicates the average percent of IS budgets spent on maintenance.

• Conduct a systems development process as an in-class exercise. Develop an implementation schedule for a class Web site. Determine whether in-house development or external software packages should be used.

• Bring a software contract or acceptance test script to the class.

• Ask students to search the Web for software contracts and test documents. Many exist. What are some of their key points?

• Discuss a contract for systems acquisition. What are some key elements?

Further Readings or Resources

Readings

Ferry, D. and N. Ferry. 2000. 77 Sure-Fire Ways to Kill a Software Project: Destructive Tactics That Cause Budget Overruns, Late Deliveries, and Massive Personnel Turnover. Publishers.

Parkinson, J. 1995. 60 Minute Software : Strategies for Accelerating the Information Systems Delivery Process (Ernst & Young Information Management Series). John Wiley & Sons.

Pigoski, T. 1996. Practical Software Maintenance : Best Practices for Managing Your Software Investment. John Wiley & Sons.

Software Development Sites





Discussion Questions

Some interesting topics of discussion in this chapter include the following:

➢ Discuss the various stages of the systems development life cycle.

➢ Discuss the differences between a systems analyst and a system designer.

Projects to Assign

1. Assign Review Questions: 3, 5, 8, and 17

2. Assign Problem Solving Exercise 2.

3. Assign Team Activity 1 or Web Exercise 2 or Case 3.

Key Terms

➢ Acceptance testing – conducting any test required by the user.

➢ Cost/Benefit analysis - an approach that lists the costs and benefits of each proposed system.

➢ Make-or-buy decision - the decision regarding whether to obtain the necessary software from internal or external sources.

➢ Patch - a minor change to correct a problem or make a small enhancement.

➢ Release - a significant program change that often requires changes in the documentation of the software.

➢ Unit testing – testing of individual programs.

➢ User documentation - written description developed for individuals who use a program, showing users, in easy-to-understand terms, how the program can and should be used.

➢ Version - a major program change, typically encompassing many new features.

➢ Volume testing - testing the application with a large amount of data.

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