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Definition and Objectives of Systems Development

Dalam dokumen business processes and information technology (Halaman 187-191)

Organizations exist in a dynamic environment, and thus, they regularly experience changes in their

Legal requirements, such as government reporting.

Level and kinds of competition.

Technologies, such as data entry devices, bar codes, and radio frequency identi- fication (RFID) tags used to record and process information.

Lines of business or kinds of business activities.

Management desire for better access to information and improved management reporting.

All of these challenges at varying times necessitate changes to organizations’ In- formation Systems. These changes may either require the creation of new Informa- tion Systems or significant modifications to existing Information Systems. Systems developmentcomprises the steps undertaken to create, modify, or maintain an or- ganization’s Information System. These steps, along with the project management concepts discussed below, guide the in-house development of Information Systems (i.e., make), as well as the acquisition of systems solutions (i.e., buy). A term often used synonymously with systems development is systems development life cycle or SDLC. The term systems development life cycle (SDLC)is used in several ways. It can mean:

1. A formal set of activities, or a process, used to develop and implement a new or modified Information System (referred to below as a systems development methodology.)

2. The documentation that specifies the systems development process referred to as the systems development standards manual.

3. The progression of Information Systems through the systems development process, from birth through implementation to ongoing use.

The “life cycle” idea comes from this last view and is the definition that we use in this text. Systems development is also an important—sometimes dominant—com- ponent of more comprehensive organizational change via business process reengineer- ing. These terms as well as “systems life cycle” and “systems analysis and design” are also used to refer to the systems development process.

170 Part III Development of Information Systems

Review Question

What is systems development?

Review Question

What is the difference between systems development and the systems development life cycle (SDLC)?

We propose the following systems development objectives:

To develop information systems that satisfy an organization’s informational, op- erational, and management requirements. Note that this objective relates to the system being developed.

To develop information systems in an efficient and effective manner.

Note that this objective relates more to the development process than to its outcome.

Systems Development Methodology

A systems development method- ologyis a formalized, standardized, documented set of activities used to manage a systems development project. It should be used when information systems are de- veloped, acquired, or maintained. Exhibit 6.1 describes the characteristics of an SDLC.

Following such a methodology helps ensure that development efforts are efficient and consistently leads to Information Systems that meet organizational needs.

Systems Development Phases, Steps, Purposes, and Tasks

Fig- ure 6.1 (page 172) presents the systems development life cycle. The right side of the figure depicts the four development phases: systems analysis, systems design, systems implementation, and systems operation. The bubbles in Figure 6.1 identify the seven development steps undertaken to complete the four phases of development. Arrows flowing into each bubble represent the inputs needed to perform that step, whereas outward-flowing arrows represent the product of a step.

Systems Analysis Chapter 6 171

Exhibit 6.1 Characteristics of a Systems Development Methodology

• The project is divided into a number of identifiable processes, each having a starting point and ending point. Each process comprises several activities, one or more deliverables, and several man- agement control points. The division of the project into these small, manageable steps facilitates both project planning and project control.

• Specific reports and other documentation, called deliverables, must be produced periodically during systems development to make development personnel accountable for faithful execution of systems development tasks. An organization monitors the development process by reviewing the deliverables that are prepared at the end of each key step. Many organizations rely on this documentation for train- ing new employees; it also provides users with a reference while they are operating the system.

• Users, managers, and auditors are required to participate in the project. These people generally provide approvals, often called signoffs, at preestablished management control points. Signoffs sig- nify approval of the development process and the system being developed. Such approvals ensure that users understand the resources needed for the project and believe that the project will have a successful outcome, thus ensuring its acceptance.

• The system must be tested thoroughly prior to implementation to ensure that it meets users’ needs.

• A training plan is developed for those who will operate and use the new system.

• Formal program change controls (see Chapter 8) are established to preclude unauthorized changes to computer programs.

• A post-implementation review of all developed systems must be performed to assess the effective- ness and efficiency of the new system and of the development process.

Review Question

What benefits are derived from using a systems development methodology?

Review Question

What are the systems development

objectives?

172 Part III Development of Information Systems

Figure 6.1 Systems Development Life Cycle

Systems Analysis

Systems Design

Systems Implementation

Systems Operation 2.0

Structured systems analysis

3.0 Systems selection

4.0 Structured

systems design

5.0 Systems implemen-

tation

6.0 Post- implementation

review 7.0

Systems mainte- nance Request

for systems

development Approved

feasibility document

External sources

Miscellaneous environmental information

Available hardware and software

Physical requirements

Logical specification

Request for proposal

Vendor proposals Hardware

and software

vendors

Approved configuration

plan

Approved systems design document Contract

Purchased software

Hardware

Project completion

report

Maintenance completion report

Post-implementation review report 1.0

Systems survey

Table 6.1 lists the key purposes and tasks associated with the seven development steps (bubbles) shown in Figure 6.1. You should take some time now to review both the table and the figure.

In the past it often took a new system years to move through the initial steps (i.e., bubbles 1 through 5 in Figure 6.1) in the life cycle. Now business moves at “Internet speed” and must develop B2B (business-to-business) and other business infrastruc- ture systems in 90 to 180 days. If they don’t, they may be put out of business or ab- sorbed by organizations that can.1

Systems development does not always proceed in the orderly, sequential course suggested by Figure 6.1. Some subset of steps may be repeated over and over until a satisfactory result is achieved. Or, we may undertake certain steps out of sequence.

Finally, systems development may be outsourced to consultants or vendors, and per- sonnel from within the organization will be part of the development team to serve as business process experts. The presentation in Chapters 6 and 7 assumes that systems development will be performed by an organization’s own systems development per- sonnel, proceeding as depicted in Figure 6.1. In Technology Insight 6.1 (page 174), we briefly describe some alternative approaches that may be used. The alternatives discussed there include who will develop the system and how the SDLC (Figure 6.1) might be altered. We also discuss alternative focuses for analysis and design—namely, data, functions, and objects.

Systems Analysis Chapter 6 173

1 Peter G. W. Keen, “Six months—Or Else” Computerworld (April 10, 2000): 48.

Table 6.1 Information Systems Development Phases, Purposes, and Tasks

Phase Purpose Tasks

Analysis (bubbles 1 and 2)* Define project goals and scope. Study the problem and the users’

Develop specifications for the new or requirements. Propose alternative revised system’s functions. problem solutions.

Design (bubbles 3 and 4) Develop an appropriate system Describe desired features (e.g. screen manifestation. layouts, business rules) in detail.

Choose software and hardware.

Write computer program specifications.

Devise implementation plans, system tests, and training.

Implementation (bubble 5) Prepare to begin using the new Write, test, and debug the computer

system. programs.

Operation (bubbles 6 and 7) Use the new system. Convert to new or revised system.

Conduct post-implementation review.

Perform systems maintenance.

*Refers to Figure 6.1.

Review Question

What are the systems development phases, steps, purposes, and tasks?

174 Part III Development of Information Systems

Dalam dokumen business processes and information technology (Halaman 187-191)