What is a System? A system is a collection of interrelated components that work together to perform a specific task.

What are the examples for Systems? Human body Plant School Office

If we consider human body it has following subsystems What is a subsystem? Each component of a system is a subsystem and carries out a part of the system task If we consider human body it has following subsystems Blood Circulatory System Digestive System Respiratory System Nervous System and etc…

Extra Curricular Activities School as a System                                                                             subsystems. Teaching & Learning Sports & Games Aesthetics Extra Curricular Activities Management

Develop Knowledge,skills,attitudes Subsystems carry out part of the system task Subsystem Task Develop Knowledge,skills,attitudes Teaching & Learning Maintain Physical & Mental Health Sports & Games Appreciating Music ,Atrs , Dancing ect.. Aesthetics Coordinate Human & Physical Resources Management

Basic Elements of a system Input Process Output Input process Output Data Processing Information

Input Input process School System Processing Output Output Students Elements of the School System ? Students Teachers Administrators Teaching tools Input Input process Teaching Examinations Presentations Seminars Class assignments Training students in the various disciplines School System Processing Output Output Educated Students

Input Processing Output Food Water Oxygen Medicine Elements of the Human System Food Water Oxygen Medicine Input Processing Human System Energy Heat Waste Carbon dioxide Output

***For additional information Open and Close Systems …… Open Systems An open system receives inputs from its environment and returns outputs to the environment. Processing Inputs Outputs Environment Environment An Open system

Open and Close Systems …… Close Systems A close systems have only internal process. No inputs from its environment and no output returns to the environment. Processing Inputs Outputs Environment Environment A close System

Computer Based Information System Manual System In this kind of systems all processes are done manually. (using papers, files, pens) Computer Based Information System A system which converts data into information using a computer known as a computer based information systems

Benefits of any type of computer based information system Ability to detect whether a particular item is available. Ability use a bar code if necessary Ability to do calculation automatically. Ability to search a record efficiently. Ability to maintain records Ability to update efficiently Work will be accurate and efficient

Differences between manual system and Computer based Information System Computer based Information Suystem

System Development Life Cycle (SDLC) SDLC is some steps to develop a new computerized system for an existing manual system or computer based system. There are 6 steps to be followed Identification of requirements Designing the solution Coding the solution Testing and Debugging Deployment of the system Maintenance of the system

SDLC cont…. To create a new computerized system, the relevant company should give the contract of developing to a “software Developing company” In “software Developing company” there is a “software Developing team” A team consist with following team members Project manager is the team leader System Analyst System Designer System Developer/ programmer/ sw engineer QA ( Quality Assauer) System Administrator

1. Identification of requirements The system Analyst is going to the relevant company, which needs the computerized system and find out what are the problems they have. Then preparing a simple document that consists all the problems they have and all the possible solutions (objectives). The problems can be, Low efficiency Less security System is too slow Time consuming Not reliable No backups Doesn’t have enough space Solutions to the above problems will be the requirements of the system.

1. Identification of requirements cont…. Before the computerized system is created, with the requirements of the system, analyst should provide the following documents, Description of the existing system Adv. N Dis adv. Of the existing system Description of the new system Adv. N Dis adv. Of the new system

1. Identification of requirements cont…. Data / Facts/Information/requirements gathering techniques Interviews Questionnaires Observations Documents sample collection prototyping

1. Identification of requirements cont…. Feasibility Study A basic study should be made to check whether the company has the required resources to develop the system.   Technical feasibility Determine whether the company has the technical expertise to handle completion of the project. Focused on gaining an understanding of the present technical resources of the organization and their applicability to the expected needs of the proposed system. Operational feasibility Determine whether the company has the sufficient human resources to provide for the new project. Economic feasibility The purpose of the economic feasibility assessment is to determine whether the company has sufficient economy and what are the economic benefits to the organization that the proposed system will provide.

2.Designing the solution In designing the solution, the system designer is drawing a model of the new system. The main tasks of the design can be considered as follows, Identification of necessary soft ware Identification of necessary Hardware Designing the user interfaces (screens) Designing the database

Other activities of Designing the solution

3.Coding the solution In development the task of building up a computerized system is done by codings. According to the database and interfaces designed by the designer, the system developer use necessary programming languages and software, to develop the system.

4. Testing and Debugging After developing the computerized system with coding, it should be tested properly to check whether there are any errors. There can be coding errors, Designing errors or requirement errors. It should be tested all the functional and non functional requirements are gained properly.

A system can be tested in four steps. Unit testing In this method each component should be tested separately to see the outputs against the given inputs. 2. Integration testing In this method test whether all the components are connected together properly to form a complete system 3. System Testing Test the system as a whole (entire system)and see its out puts for the given inputs 4. Acceptance testing check the system with the user to see whether the user approve or request for more improvements

5. Deployment of the system After testing and correcting all the errors of the new computerized system, it should be deployed (implemented) in the relevant organization. deployment methods Direct deployment Parallel deployment Pilot deployment Phase deployment

1. Direct deployment 2. parallel deployment Directly replace the new system and totally terminate the existing system. Then continue the process with new system. Both Current existing system and new system are running for a certain period of time. Once the user got use to the new system terminate the existing system and continue the process with new system. 2. parallel deployment

3. Pilot deployment System is deploying for a selected part of the company. If that successful move to another part to deploy. System is deployed in stages. Success of each stage will leads to deployed the next stage. 4. Phased deployment

6.Maintenance of the system What happens during the rest of the software's life, changes, correction, additions, and moves to a different computing platform and more. This, the least glamorous and perhaps most important step of all, goes on seemingly forever

Requirements for maintenances