Lead Black Slide

Lead Black Slide

Powered by DeSiaMore 2

Chapter 13

Developing and Managing Information Systems


Our Agenda People in Information Systems

Development The System Development Process System Development Tools A Case Study of Information

Systems Development Other System Development

Approaches


Our Agenda (cont’d.) Individual Information Systems

Development Electronic Commerce Systems

Development Business Process Reengineering


Learning Objectives Explain the roles of the people who

are involved in information system development.

Outline the phases and steps in the information system development process.


Learning Objectives (cont’d.) Describe the user’s involvement in

each phase of the system development process.

Explain the purpose of common tools used for system development.

Explain the use of prototyping and rapid application development in system development.


Learning Objectives (cont’d.) Explain how the system

development process can be adapted to the development of individual information systems.

Describe the process of developing electronic commerce systems.

Describe the purpose of business process reengineering.


People in Information System Development



People in Information Systems Development Systems analysts follow a step-by-

step process to develop information systems.

Information systems are usually developed by a group of people who form a project team.


The System Development Process



The Systems Development Process The system development

process, which also called the System Development Life Cycle (SDLC) is divided into five main phases:

1. System planning2. System analysis3. System design4. System implementation5. System maintenance


System Planning System planning is the phase in

which the systems analyst decides whether a new information system should be developed. The systems analyst conducts a

feasibility analysis. A cost/benefit analysis is prepared.


System Analysis During system analysis, the analyst

studies the existing and determines what the new system must do. Develop user requirements Develop a conceptual design Evaluate hardware and software

alternatives Packaged software Custom software


System Design During system design, the analyst

specifies how the new system will function. Understanding what the new system

must do Understanding how the system will do it Describing design details including

layouts of screens, forms and reports; specifications for all hardware; descriptions of all programs.


System Implementation During system implementation, the

systems analyst acquires the components of the system – such as programs – tests the system, and changes over to the new system.


System Implementation (cont’d.) Four methods of converting to the new

system: Plunge – old system is turned off, new one is

turned on. Phased – new system is divided into parts

with one part phased in at a time. Pilot – new system is installed in a part of

the organization. Parallel – old and new systems are used

simultaneously for a period of time.


System Maintenance System maintenance involves

modifying the system during its life to meet new requirements.

Maintenance is required for three reasons:

1. Errors found that were not detected in testing

2. A new function is to be added to the system

3. The requirements have changed


System Development Tools



System Development Tools Data Flow Diagrams (DFD) Entity-Relationship diagram (ER) CASE tools


Data Flow Diagrams A tool many analysts use to show the

flow of data in an information system. The diagram uses symbols with different

shapes to indicate how data flows in the system. They are: Process – a rounded corner rectangle External entity – a rectangle Data store – an open rectangle Data flow – an arrow


Entity-Relationship Diagram An entity is something about which

data is stored in a database. A relationship is an association

between entities. An entity-relationship diagram

shows the entities and relationships between entities in a database.


CASE Tools CASE – Computer Aided Software

Engineering – tools are computer based tools such as those for system development.


A Case Study in Information System Development



A Case Study in Information Systems Development Sportswear Enterprises is

considering requesting a sales system analysis. The case study considers the five steps in the system development life cycle.


Other System Development Approaches



Other System Development Approaches Three alternative approaches to

developing information systems: Prototyping Rapid Application Development (RAD) Object-oriented analysis and design


Prototyping Prototyping involves the systems

analyst obtaining informal and incomplete requirements for the system and developing a prototype, which is a partial version of the system that acts like the real system but may not perform all the required functions of the system.


Rapid Application Development Prototyping is used to determine

user requirements. CASE tools speed up the analysis

and design. The prototype is often developed

into the final system. Significant user involvement is

required.


Object-Oriented Analysis and Design Object-oriented analysis and

design involves combining the data and processing methods usually specified in the DFD and ER diagrams respectively.

They are combined to form an object.


Individual Information System Development



Individual Information System Development The five steps of the SDLC serve as

a general guide. Individual information system

planning starts when the user recognizes a problem or a need.

Must consider whether personal technical skills are adequate.


Electronic Commerce System Development



Electronic Commerce System Development While similar to the steps in the

SDLC, there are notable differences: In e-commerce systems, the main

user is the customer. Software selection is limited to the

special e-commerce software.


Electronic Commerce System Development (cont’d.) Design of an e-commerce system

involves two main parts: Front end – is what the customer sees

when they use the system. Back end – provides the capabilities

necessary for completing the customer’s order including inventory control and product distribution.


Electronic Commerce System Development (cont’d.) Publishing the system is the

process of setting up the system on a server and making it available through the Internet.


Business Process Reengineering



Business Process Reengineering Business Process Reengineering

(BPR) involves completely redesigning the business processes, which are groups of activities or tasks that accomplish things for a business.

BPR is not gradual improvement, but rather radical redesign of business processes.



Key Terms


Key Terms Business Process Business Process Reengineering (BPR) CASE Conceptual Design Cost/Benefit Analysis Data Flow Diagram (DFD)

Entity-Relationship (ER) Diagram Feasibility Analysis Legacy System Object-Oriented Analysis and Design Outsourcing Packaged Software Project Team


Key Terms (cont’d.) Prototype Prototyping Rapid Application Development (RAD) System Analysis System Design System Development Life Cycle (SDLC) System Implementation

System Maintenance System Planning Systems Analysis User Requirements


Summary People in Information Systems

Development The System Development Process System Development Tools A Case Study of Information

Systems Development Other System Development

Approaches


Summary (cont’d.) Individual Information Systems

Development Electronic Commerce Systems

Development Business Process Reengineering

Final Black Slide

Date post:	25-Feb-2016
Category:	Documents
Upload:	amina
View:	33 times
Download:	2 times

Lead Black Slide

Documents