System Life Cycle – Classical definition
A system is a set of interacting elements that responds to inputs producing outputs. The events which together make up the development, operation and maintenance of such a computer system or information management system may be referred to as the ‘System Life Cycle’.
The different elements of a system life cycle are –
1. Initial Study –
Initial study is the first stage in the system life cycle. Initial study is made on the basis ofa user request to computerize his/her system/need. A feasibility study is undertaken by the concerned system analyst after studying the requirement definition and he can make decisions as to whether or not implement such a system. Take the case of a fully computerized Recording studio.
2. System Design –
Once the initial study is agreed showing that the system is feasible, then the system specification is made which shows the various information flows, file storage and other document requirements. A good system specification should include the details of what type of programs is to be used, how they can be made and their interaction with files/db/documents/objects which they provide or consume. In the case of a recording studio, specification has to be made about the different programs that will control the various recording procedures like controlling pitch and tone, editing etc. The specification must also contain documents about programs that are used to modify and control a particular chord. It must also specify the methods by which such a program can be made. A good system specification also includes a user document which shows how the system would work in future once it is automated.
3. Program specification-
Once the specification for the computerized recording studio is accepted, program specification is prepared by a senior programmer. A program specification must include the definitions of the input and outputs, their description and the relationship between them. A good program specification will show the clear structure of the program to the formulated. For this, one may use data flow diagrams or UML.
In the case of the recording studio, the program specification must show the program specification must show the various inputs to the system, how they are processed and stored in various files and how they can be used for various purposes. The programmer should ensure that the specifications complete and clear before he begins the design process.
4. Program Design & Coding –
The program design will include proper descriptions of all inputs, outputs, and process and storage requirements of the program. The design of a particular program must be consistent with the overall system specification with particular reference to the format and content of data flows. The programmer can now code the program using appropriate coding standards.
The program design made for the computerized recording studio can be checked by conducting a trial/demo recording and if any drawbacks are found, the design process can be repeated again. If the design is acceptable, it is implemented.
5. System testing & installation
Once the program design for the recording procedure is implemented and is unit tested, system testing is undergone in which the new system is run for testing its efficiency. If found that the recording is perfect, system installation is made. This can be done by live parallel running or by pilot running. In parallel running, the old and the new system are run closely together and results are compared. But, in the case of computerizing a recording studio, this won’t be necessary as the immense recording possibilities offered by such a system will be more than anything.
6. Live Run and Maintenance –
Computer Technology is advancing every day and many new software, hardware etc are available in the market. Using these latest technologies, the existing recording system may be modified. So, again the user comes up with request (in this case a maintenance/change request) and again the whole life cycle is repeated.
Article copyright (c) 2010 – Deepesh Joseph ([email protected])