System Development Concept

System development concept is a systematic process for developing the system. A system is a combination of interrelated components which may contain the hardware of the software. A system is a collection of elements that are organized for a common purpose.

an information system is used for decision making. It provides the required information to the higher level management or the authority.

Different types if Information System are:

Management Information System

Decision Automation System

Transaction Processing System

Office Processing System

Expert System

System Development Life Cycle

SDLC is a systematic process of developing a new system or modifying the older one. It contains various stages through which a system will be developed. These stander steps help for developing an appropriate, errors free, system.

The steps are:

1.    System Study
2.    System Analysis
3.    System Design
4.    System Development
5.    System Testing
6.    System Implementation
7.    System Maintenance

System Study:

This is also know as need analysis and feasibility study stage. In this stage the requirements of the user are identified. The need of the new system is identified and other alternatives to solve the user problems are also identified.

For identifying the user requirements methods such as question answer, on site observation, etc. are used. According to the collection of the information the needs of the user is identified and its alternatives are also defined.

Feasibility Study

Feasibility study is the primary stage of the system. To check, weather to proceed with the system. It determines weather it is worthwhile to develop the purpose system of not.

It is required to determine cost/benefits of the system.

It is possible to develop or not.

It can be completed in the defined time period or not.

It is legally accepted or not.

Types of Feasibility Study:

Economic Feasibility:

This is concern with return on the investment. It calculates the cost/benefits analysis. It helps to determine the system is affordable and beneficial or not.

Technical Feasibility:

This is concern with ability of the technical manpower and the technology. It determines weather the technology to be used is available or not. Technical manpower to operate the system is available or not.

Schedule Feasibility:

This is concern with the time period to complete the system. To determine weather the system will be completed in the fixed time period or not.

Legal and Contractual Feasibility:

The legal and the contractual issues should be studied before developing the system. Legal issues deals with the system is legally accepted or not. Legal issues like copy right, trade mark, labor law, etc. should be concerned.

Behavioral Feasibility:

It is concern with behavioral approach of the employees and the share holders towards the system. Usually the employees are against the new system due to fear of the technology, loss of the job, displacement of the manpower.

Operational Feasibility:

This feasibility study is concern with the business problems and their solution. It identifies how the new system will helps in business operation.

System Analysis:

In this stage the requirements of the user are analyzed and the final outcome of this stage will be identified of the purposed system, i.e. it will explain what system will be developed. System Analyst will be involved in identification of the required and analyzing the system.

System Design:

In this phase, the analysis’s reports will be converted into detail design. This stage explains how the system will be developed, what are the main components of system operates. For designing tools like flow charts, Algorithm, Decision Table, Decision Tree, Pseudo code, DFD (Data Flow Diagram) E-R Diagram (Entity- Relationship), Porto Type, etc. are used.

System Design can be done by either of two methods.

Top-Down Method

Bottom-Up Method

In top down design, the whole the system is design and its smaller components are design latter, where as in bottom up design, the small components are design at first and the components are combined to create the large design of the whole system.

System Development:

In this stage the actual system is developed using the designs prepared by system analysis. In software system programmers develop the software, using a programming language. System developers are actually less experience than system analysis and they work on the guidance of the system analysis.

In this stage, technical writers prepare the technical document of the system. This document can used to upgrade and maintain the system.

System Testing:

System testing is the process of examining the newly developed system to determine weather it contains errors or not, this system verification involves weather the newly developed system meets the used requirements or not after this stage, he system will be ready for the user. The different testing processes are:

System Testing

Unit Testing

Black-box Testing

White-box Testing

Alpha Testing

Beta Testing

User Acceptance Testing

System Testing:

It is the process testing the whole system after the individual components are tested and combined together. System testing is initial done by the developer and then by the target user.

Unit Testing:

It is the process of testing the individual components of the system.

Black-box Testing:

In the black box testing the testing process and its results are hidden from the general users. The test process, its result, errors corrections are not known or available to the users.

White-box Testing

It is also called glass box testing. In this testing process, the test process, its results, errors corrections are made available to the users.

Alpha Testing:

If the testing process is done by the developer then, it is known as alpha testing. It is the initial process of testing process used for both unit and system testing.

Beta Testing:

It is the process of testing the newly developed system by the target group of the users. During this testing process, the system is also known as beta version system.

User Acceptance Testing

It is the testing process done by the user of the system before it is actually implemented. User checks if the new system is acceptable or not.

System Implementation:

After the system is tested and verified it is started to use in he daily operation of the user. System implementation means to start to use the newly developed system. It is also known as system conversion. The different system implementation techniques used are:

Direct Conversion:

Parallel Conversion:

Phased Conversion:

Pilot Conversion:

Direct Conversion:

In this implementation technique the older system is stopped and new system is started at once. This technique is easier to implement but contains high risk. If the new system doesn’t operate properly chance of data lost exists.

Parallel Conversion:

In this implementation process both new an old system is used parallel Direct Conversion. For certain time period, when new system provides satisfactory result the older system is stopped to be used. It requires double operation initially but has low risk of data loss.

Phased Conversion:

In this implementation technique all users starts using new system but they used component by component. i.e. A small component is implemented first and it is generally increased to implement whole system. It can only be used when a system contains multiple components.

Pilot Conversion:

In this technique the system is first used in the small unit of the organization or the branch, if the provides satisfied result then it is gradually used in other branches or units.

System Maintenance:

System maintenance is done to upgrade and modified the system after it is used. After implementation stage the identified errors are maintained or removed through this process. It is also done to modified the system according ti the users changing needs. this process continues till the system is used for maintenance process it follows the same system development life cycle.