Ch. 12 Intro to Data Processing (Systems Analysis & Design)

Preliminary Investigation (1)

First phase of the systems life cycle. It involves defining the problem, suggesting alternative systems, and preparing a short report. This report will help management decide whether to pursue the project further - determines the need for a new system.

Careers in IT - Systems Analyst

Follows the steps described in the systems life cycle. Analysts plan and design new systems or reorganize a company's computer resources to best utilize them. Analysts follow the systems life cycle through all its steps: preliminary investigation, analysis, design, development, implementation, and maintenance.

Systems Development (4)

Fourth phase of systems analysis. It has three steps: (1) acquiring software, (2) acquiring hardware, (3) testing the new system.

Direct Approach

The conversion is done simply by abandoning the old and starting up the new. This can be risky. If anything is still wrong with the new system, the old system is no longer available to fall back on.

System Maintenance (6)

Sixth and last phase. This phase is a very important, ongoing activity. Most organizations spend more time and money on this phase than on any of the others. Maintenance has two parts: (1) a systems audit (2) a periodic evaluation.

Parallel Approach

The old and new systems are operated side by side until the new one proves to be reliable. This approach is low risk. If the new system fails, the organization can just switch to the old system to keep going. However, keeping enough equipment and people active to manage two systems at the same time can be very expensive. Thus, the parallel approach is used only in cases in which the cost of failure or of interrupted operation is great.

Systems Design (3)

Third phase of systems analysis. Consists of three tasks: (1) designing alternative systems, (2) selecting the best system, (3) writing a systems design report.

Periodic Evaluation

All systems are evaluated to determine whether they are meeting the goals and providing the service they are supposed to.

Phased Approach

The new system is implemented gradually over a period of time. The entire implementation process is broken down into parts or phases. Implementation begins with the first phase, and once it is successfully implemented, the second phase begins. This process continues until all phases are operating smoothly. Typically, this is an expensive proposition because the implementation is done slowly. However, it is certainly one of the least risky approaches.

Pilot Approach

The new system is tried out in only one part of the organization. Once the system is working smoothly in that part, it is implemented throughout the rest of the organization. The pilot approach is certainly less expensive than the parallel approach. It also is somewhat riskier. However, the risks can be controlled because problems will be confined to only certain areas of the organization. Difficulties will not affect the entire organization.

Systems Analysis & Design

A six phase problem-solving procedure for examining and improving an information system. The six phases make up the 'systems life cycle.' 1. Preliminary investigation 2. Systems analysis 3. Systems design 4. Systems development 5. Systems implementation 6. Systems maintenance

Rapid Applications Development (RAD)

Involves the use of powerful development software and specialized teams as an alternative to the systems development life cycle approach. Time for development is shorter and quality of the completed systems development is better, although cost is greater.

System Implementation / Conversion (5)

It is the process of changing—converting—from the old system to the new one and training people to use the new system.

Systems Audit

The system's performance is compared to the original design specifications. This is to determine whether the new procedures are actually furthering productivity. If they are not, some redesign may be necessary.

Systems Design Report

The systems design report is prepared for higher management and describes the alternative designs. It presents the costs versus the benefits and outlines the effect of alternative designs on the organization. It usually concludes by recommending one of the alternatives.

Types of Conversion

There are four approaches to conversion: (1) Direct approach (2) Parallel approach (3) Pilot approach (4) Phased approach

Systems Analysis (2)

This second phase of the systems life cycle determines the requirements for a new system. Data is collected about the present system and analyzed, and new requirements are determined. We are not concerned with a new design here, only with determining the requirements for a new system. Systems analysis is concerned with gathering and analyzing the data. This usually is completed by documenting the analysis in a report.

Prototyping

To build a model or prototype that can be modified before the actual system is installed. Users would try it out and provide feedback to the systems analyst. The systems analyst would revise the prototype until the users felt it was ready to put into place. Typically, the development time for prototyping is shorter; however, it is sometimes more difficult to manage the project and to control costs.