The Computer Revolution/Software/System Development

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System Development[edit]

System development comes into play when a new system is needed or when an existing system has problems. The definition of system development is based of the six phases; analyzing, design or modify, acquiring new software or hardware, training, and lastly is ensuring the system works properly. As times have advanced the need for more information and processing have procured system development to make the changes to current systems or put new systems in place to be able to provide the necessary information which all ties in with intelligence and architecture on a enterprise or business level. The process goes into more detail as shown below breaking down each phase further to better understand system development.

SDLC

Source: Understanding Computers: Today and Tomorrow, 13th Edition - Course Technology, Cengage Learning

The Six Phases of Systems Analysis & Design[edit]

The 1st Phase[edit]

Preliminary investigation

1. Conduct the preliminary analysis

2. Propose alternative solutions

3. Describe the costs & Benefits

4. Submit a preliminary plan

The 2nd Phase[edit]

Systems analysis

'1. Gather data'

In gathering data, you will reviw written documents, interview employees and managers, develop questionnarires, and observe people and provesses at work.

'2. Analyze the data'

Once the data has been gathered, you need to come to grips with it and analyze it. Many analytical tools, or modeling tools, are availabe. Modeling tools enable a system. an example of a modeling tool is a data flow diagram (DFD), which graphically shows the flow of data through a system that is, the essential processes of a system, along with inputs, outputs, and files.

'3. Write a report'

Once you have completed the analysis, you need to document this phase. This report to management should have three parts. First, it should explain how the existing system works. Second, it should explain the problems with the existing system. Finally, it should describe the requirements for the new system and make recommendations on what to do next.

The 3rd Phase[edit]

Design the system

1. Do a preliminary design'

A preliminary design the general functional capabilities of a proposed information system. It reviews the system requirements and then considers major components of the system. Prototyping refers to using workstations, Case tools, and other software applications to build working models of system components so that they can be quickly tested and evaluated.

2.Do a detail design'

A preliminary design describes how a proposed information system will delver the venereal capabilities described in the preliminary design. the detail design usually considers the following parts of the system n this order : output requirements, input requirements, storage requirements, and system controls and backup.

3. Write a report'

All the work of the preliminary and detail designs will end up in a large, detailed report. When you hand over this report to senior management, you will probably also make some sort of presentation or speech

The 4th Phase[edit]

Develop the system

1.Develop or acquire the software

During the design stage, the systems analyst may have had to address what is called the “make-or –buy” decision, but that decision certainly cannot be avoided now.

2.Acquire hardware

3.Teste tha system

-Unie testing

-System testing

The 5th Phase[edit]

Implements the System

1. Covert to the new system

-Direct implementation

-Parallel implementaion

-Phased implementaion

-Pilot implementation

The 6th Phases[edit]

Maintain the System

Adjusts and improves the system by having system audits and periodic evaluations and by making changes based on new conditions.