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Systems Analysis




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Whether you are a part of a team that is developing a complex corporate information system, or you are developing a small information system for your own use, you will be more likely to succeed if you analyze the purpose of the information system, carefully design the system, test it thoroughly, and document its features. In this text you’ll learn about the planning and analysis that’s required for an information system.

 

SYSTEM DEVELOPMENT LIFE CYCLE

An information system progresses through several phases as it is developed, used, and finally retired. These phases are referred to as a system development life cycle – usually referred to as SDLC.

Planning

Phase Analysis

Phase Design

Phase Implementation

Phase Maintenance

Phase

The originalwaterfall SDLC,shown above, approaches each phase as a discrete stepin the development process. One phase is supposed to be completed before the next phase can begin.

The SDLC is an outline of a process that helps develop successful information systems. The process of planning and building and information system according to the SDLCis referred to as systems analysis and design.

 

Planning Phase

For creating an information system it’s important to have a plan. Initial plans for an information system are developed during the planning phase. The planning phase for an information system project includes the following activities:

- Assemble the project team

- Justify project

- Choose development methodology

- Develop a project schedule

- Produce a Project Development Plan.

The main goal of these activities is to create a Project Development Plan.Before the project proceeds beyond the planning phase, the Project Development Plan must typically be reviewed and approved by the management. This planning document includes:

A short description of a project, including its scope

A justification for the project, which includes an estimate of the project costs and potential financial benefits

A list of project team participants

A schedule for the project, including an outlineof its phases

Project planning begins in the planning phase but stretches throughout the entire project. As the project takes shape, project managers break down the work into tasks and milestones, which can be scheduled and assisted. As tasks are completed, the schedule can be updated and adjusted. Project management software is an effective tool for planning and scheduling. It helps manages track and visualize the complex interactions between tasks. Popular examples include open source software, such as Open WorkBench, and commercial software, such as Microsoft Project.



 

ANALYSIS PHASE

The analysis phase begins after the project team selects a development methodology, draws up the Project Development Plan, and receives permission to proceed from management. The goal of the analysis phaseis to produce a list of requirements for a new or revised information system.

Typically, a new information system is designed to replace a system or process that is already in place. It is important to study the current system to understand its strengths and weaknesses before planning a new system.

System requirementsare the criteria for successfully solving problems identified in an information system. There requirements guide the design and implementation for a new or updated information system. They also serve as an evaluation checklist at the end of the development project, so they are sometimes called success factors.A new or updated information system should meet the requirements the project team defines.



The project team determines requirements by interviewing users and studying successful information system that solve problems similar to those in the current system. Another way to determine requirements is to construct a prototype as an experimental or trial version of an information system. Often the prototype is not a fully functioning system because it is designed to demonstrate only selected features that might be incorporated into a new information system. A systems analyst shows the prototype to users, who evaluate which features of the prototype are important for the new information system.

The project team can use a variety of tools to diagram the current system and specify what it does. These tools help the team produce documentation that is also useful in later phases of the SDLC. It can be a complex task; however, to maintain this documentation as the project progresses a CASE tool is used. A CASE tool (Computer-Aided Software Engineering) is a software application designed for documenting system requirements, diagramming current and proposed information systems, scheduling development tasks and developing compute programs. CASE tools automate many of the routine housekeeping tasks required for systems analysis and design, such as changing the labels used to describe elements in a database.



After the project team studies the current system and then determines what the new system should do, system requirements are incorporated into a document called a System Requirements Report that describes the objectives for an information system. If management or the project sponsor approves the report, the project can move on to the design phase.

 

 

Comprehension check. Indicate the paragraph where the following ideas are found in the text.

1. These plans are developed during the planning phase.

2. You can determine the system requirements by this way.

3. A list of requirements for a new system should be produced at this phase.

4. Several phases are required for information process.

5. A plan is inseparable part of an information system.

6. There are plenty of tools for diagramming and specifying the current system.


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