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Slide Presentasi Chapter 12-13 Principles of Information Systems
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Systems Development
Principles of Information Systems, Seventh Edition 2
• Effective systems development requires a team effort from stakeholders, users, managers, systems development specialists, and various support personnel, and it starts with careful planning
• Identify the key participants in the systems development process and discuss their roles
• Identify important system performance requirements of transaction processing applications that run on the Internet or a corporate intranet or extranet
Principles of Information Systems, Seventh Edition 3
• Systems development often uses tools to select, implement, and monitor projects
• Discuss the key features, advantages, and disadvantages of the traditional, prototyping, rapid application development, and end-user systems development life cycles
• Identify several factors that influence the success or failure of a systems development project
Principles of Information Systems, Seventh Edition 4
• Systems development starts with investigation and analysis of existing systems
• State the purpose of systems investigation
• Discuss the importance of performance
• State the purpose of systems analysis and discuss some of the tools and techniques used in this phase of systems development
Principles of Information Systems, Seventh Edition 5
• Designing new systems or modifying existing ones should always be aimed at helping an organization achieve its goals
• State the purpose of systems design and discuss the differences between logical and physical systems design
Principles of Information Systems, Seventh Edition 6
• The primary emphasis of systems implementation is to make sure that the right information is delivered to the right person in the right format at the right time
• State the purpose of systems implementation and discuss the various activities associated with this phase of systems development
Principles of Information Systems, Seventh Edition 7
• Maintenance and review add to the useful life of a system but can consume large amounts of resources. These activities can benefit from the same rigorous methods and project management techniques applied to systems development.
• State the importance of systems and software maintenance and discuss the activities involved
• Describe the systems review process
Principles of Information Systems, Seventh Edition 8
An Overview of Systems Development: Participants in Systems Development
• Development team
• Responsible for determining the objectives of the information system and delivering a system that meets these objectives
• Usually consists of stakeholders, users, managers, systems development specialists, and various support personnel
Principles of Information Systems, Seventh Edition 9
Figure 12.1: Systems analyst plays an important role in the development team
Principles of Information Systems, Seventh Edition 10
Initiating Systems Development
• Systems development begins when an individual or group capable of initiating organizational change perceives a need for a new or modified system
• Systems development initiatives arise from all levels of an organization
• Systems development initiatives are both planned and unplanned
• Systems development projects may be initiated for a number of reasons
Principles of Information Systems, Seventh Edition 11
Figure 12.2: Typical Reasons to Initiate a Systems Development Project
Principles of Information Systems, Seventh Edition 12
Establishing Objectives for Systems Development: Performance Objectives
• Output quality or usefulness
• Output accuracy
• Output format quality or usefulness
• Speed at which output is produced
• Scalability of the resulting system
Principles of Information Systems, Seventh Edition 13
Cost Objectives
• Development costs
• Uniqueness costs
• Fixed investments
• Ongoing operating costs
Principles of Information Systems, Seventh Edition 14
Web-Based Systems Development: The Internet, Intranets, Extranets, and
E-Commerce
• Internet technology enables companies to extend their information systems beyond their boundaries to reach their customers, suppliers, and partners
• Dynamic core business application that runs over the Web
• Must be reliable and fault tolerant
• Must integrate with existing infrastructure
• Development and maintenance must be quick and easy
Principles of Information Systems, Seventh Edition 15
Systems Development Life Cycles
• The systems development process is also called a systems development life cycle (SDLC)
• The later in the SDLC an error is detected, the more expensive it is to correct
Principles of Information Systems, Seventh Edition 16
Systems Development Life Cycles (continued)
• Common systems development life cycles:
• Traditional
• Prototyping
• Rapid application development (RAD)
• End-user development
Principles of Information Systems, Seventh Edition 17
Figure 12.6: The Traditional Systems Development Life Cycle
Principles of Information Systems, Seventh Edition 18
The Traditional Systems Development Life Cycle
• Systems investigation: problems and opportunities are identified and considered in light of the goals of the business
• Systems analysis: study of existing systems and work processes to identify strengths, weaknesses, and opportunities for improvement
• Systems design: defines how the information system will do what it must do to obtain the problem solution
Principles of Information Systems, Seventh Edition 19
The Traditional Systems Development Life Cycle (continued)
• Systems implementation: the creation or acquiring of various system components detailed in the systems design, assembling them, and placing the new or modified system into operation
• Systems maintenance and review: ensures the system operates and modifies the system so that it continues to meet changing business needs
Principles of Information Systems, Seventh Edition 20
Prototyping
• An iterative approach to the systems development process
• Operational prototype: a functioning prototype that accesses real data files, edits input data, makes necessary computations and comparisons, and produces real output
• Nonoperational prototype: a mock-up, or model, that includes output and input specifications and formats
Principles of Information Systems, Seventh Edition 21
Rapid Application Development, Agile Development, Joint Application Development, and Other Systems Development Approaches
• Rapid application development (RAD): a systems development approach that employs tools, techniques, and methodologies designed to speed application development
• RAD makes extensive use of the joint application development (JAD) process for data collection and requirements analysis
Principles of Information Systems, Seventh Edition 22
The End-User Systems Development Life Cycle
• Any systems development project in which the primary effort is undertaken by a combination of business managers and users
• End-user-developed systems can be structured as complementary to, rather than in conflict with, existing and emerging information systems
Principles of Information Systems, Seventh Edition 23
Table 12.5: When to Use Outsourcing for Systems Development
Principles of Information Systems, Seventh Edition 24
Table 12.5: When to Use Outsourcing for Systems Development (continued)
Principles of Information Systems, Seventh Edition 25
Factors Affecting Systems Development Success
• Degree of change• Continuous improvement versus reengineering• Managing change
• Quality and standards
• Use of project management tools
• Use of Computer-Aided Software Engineering (CASE) tools• Automate many of the tasks required in a systems
development effort and enforce adherence to the SDLC
Principles of Information Systems, Seventh Edition 26
Systems Investigation
• What primary problems might a new or enhanced system solve?
• What opportunities might a new or enhanced system provide?
• What new hardware, software, databases, telecommunications, personnel, or procedures will improve an existing system or are required in a new system?
• What are the potential costs (variable and fixed)?
• What are the associated risks?
Principles of Information Systems, Seventh Edition 27
Figure 12.12: The Systems Investigation Team
Principles of Information Systems, Seventh Edition 28
Figure 12.13: Technical, Economic, Legal, Operational, and Schedule Feasibility
Principles of Information Systems, Seventh Edition 29
The Systems Investigation Report
• Summarizes the results of systems investigation and the process of feasibility analysis
• Recommends a course of action: continue on into systems analysis, modify the project in some manner, or drop it
Principles of Information Systems, Seventh Edition 30
Systems Analysis
• Steps of a formalized analysis procedure:
• Assembling the participants for systems analysis
• Collecting appropriate data and requirements
• Analyzing the data and requirements
• Preparing a report on the existing system, new system requirements, and project priorities
Principles of Information Systems, Seventh Edition 31
The Systems Analysis Report
• The systems analysis report should cover:
• The strengths and weaknesses of the existing system from a stakeholder’s perspective
• The user/stakeholder requirements for the new system (also called the functional requirements)
• The organizational requirements for the new system
• A description of what the new information system should do to solve the problem
Principles of Information Systems, Seventh Edition 32
Systems Design
• Answers the question “How will the information system do what it must do to solve a problem?”
• Has two dimensions: logical and physical
• Logical design: description of the functional requirements of a system
• Physical design: specification of the characteristics of the system components necessary to put the logical design into action
Principles of Information Systems, Seventh Edition 33
Logical Design
• Output requirements
• Input requirements
• Process requirements
• File and database requirements
Principles of Information Systems, Seventh Edition 34
Logical Design (continued)
• Telecommunications requirements
• Procedure requirements
• Controls and security requirements
• Personnel and job requirements
Principles of Information Systems, Seventh Edition 35
Physical Design
• Hardware specifications
• Software specifications
• Database specifications
Principles of Information Systems, Seventh Edition 36
Physical Design (continued)
• Telecommunications specifications
• Personnel specifications
• Procedure and control specifications
Principles of Information Systems, Seventh Edition 37
Design of System Security and Controls
• Preventing, detecting, and correcting errors
• Disaster planning and recovery
• Disaster planning: the process of anticipating and providing for disasters
• Disaster recovery: the implementation of the disaster plan
• Hardware backup
Principles of Information Systems, Seventh Edition 38
Design of System Security and Controls (continued)
• Disaster planning and recovery (continued)
• Software and database backup
• Telecommunications backup
• Personnel backup
• Systems controls: rules and procedures to maintain data security
Principles of Information Systems, Seventh Edition 39
The Design Report
• Primary result of systems design
• Reflects the decisions made and prepares the way for systems implementation
Principles of Information Systems, Seventh Edition 40
Figure 13.11: Typical Steps in Systems Implementation
Principles of Information Systems, Seventh Edition 41
Systems Operation and Maintenance
• Systems operation: use of a new or modified system
• Systems maintenance: checking, changing, and enhancing the system to make it more useful in achieving user and organizational goals
Principles of Information Systems, Seventh Edition 42
Systems Review
• Process of analyzing systems to make sure that they are operating as intended
• Often compares the performance and benefits of the system as it was designed with the actual performance and benefits of the system in operation
• Event-driven review: review triggered by a problem or opportunity such as an error, a corporate merger, or a new market for products
• Time-driven review: review performed after a specified amount of time
Principles of Information Systems, Seventh Edition 43
Factors to Consider During Systems Review
• Mission• Organizational goals• Hardware and software• Database• Telecommunications• Information systems
personnel• Control
• Training• Costs• Complexity• Reliability• Efficiency• Response time• Documentation
Principles of Information Systems, Seventh Edition 44
Summary
• Systems development begins when an individual or group capable of initiating organizational change perceives a need for a new or modified system
• Information systems planning is the translation of strategic and organizational goals into systems development initiatives
• Aligning organizational goals and IS goals is critical for any successful systems development effort
• Common systems development life cycles are traditional, prototyping, rapid application development (RAD), and end-user development
Principles of Information Systems, Seventh Edition 45
Summary (continued)
• Phases of the traditional systems development life cycle: systems investigation, systems analysis, systems design, systems implementation, and systems maintenance and review
• During systems investigation, problems and opportunities are identified and considered in light of the goals of the business
• Systems analysis involves the study of existing systems and work processes to identify strengths, weaknesses, and opportunities for improvement
Principles of Information Systems, Seventh Edition 46
Summary (continued)
• Computer-Aided Software Engineering (CASE) tools automate many of the tasks required in a systems development effort and enforce adherence to the SDLC
• Object-oriented systems development is an approach to systems development that combines the logic of the systems development life cycle with the power of object-oriented modeling and programming
Principles of Information Systems, Seventh Edition 47
Summary (continued)
• Systems design answers the question “How will the information system do what it must do to solve a problem?”
• Systems design has two dimensions: logical and physical
• Logical design is description of the functional requirements of a system
• Physical design is specification of the characteristics of the system components necessary to put the logical design into action
Principles of Information Systems, Seventh Edition 48
Summary (continued)
• Steps of systems implementation: hardware acquisition, software acquisition, user preparation, personnel: hiring and training, site preparation, data preparation, installation, testing, start-up, and user acceptance
• Systems operation is the use of a new or modified system
• Systems maintenance involves checking, changing, and enhancing the system to make it more useful in achieving user and organizational goals
Principles of Information Systems, Seventh Edition 49
Summary (continued)
• Systems review is the process of analyzing systems to make sure that they are operating as intended
• Event-driven review is triggered by a problem or opportunity such as an error, a corporate merger, or a new market for products
• Time-driven review is performed after a specified amount of time