¶ … Systems Life Cycle and Database Systems Including
> Define systems, including why systems have a beginning and end.
> Discuss the importance of integrating a life cycle into the plan for development of a database
> Consider your organization or a business with which you are familiar. Provide examples of the database system it uses, its systems life cycle and how they are related. Is this effective? Why or why not?
> If your organization does not use a formal database system, what should it be implementing? Why?
The systems lifecycle in systems engineering refers to a system that addresses all phases of the engineering process. This includes: system conception, design and development, production and/or construction, distribution, operation, maintenance and support, retirement, phase-out and disposal.
As elaboration of each, we have:
1. Initial idea: this regards what the project is about, its purpose, and ways of accomplishing it.
Feasibility study -- how long the project should take, its scope and deadline. This is drawn up by Management who also assesses feasibility of idea in terms of economic and organizational concepts. Smaller projects omit this stage
3. Requirements analysis -- These are business options to the problem which may be supported by technical documents such as high-level DFD's, Logical Data Models (LDM) and Work Practice Models and present financial and other risks.
4. Systems analysis and specifications -- This provides a logical model of the system and gives precise details of what it is going to do without going into how it is going to do it.
5. Systems Design - this stage deals with how the requirements of the system are going to be implemented. A number of designs will be generated and the one that comes the closest to the idea and involves least cost and hassle as well as utilization of labor will be selected for employment.
6. Development -- program code is written. Each unit is tested to...
Testing -- the life cycle incorporates various layers of testing. these include:
Unit testing -- performed in development stage
Link testing - that all program work well together
System testing -- that the system as a whole performs
User acceptance testing - by users to ensure that system is usable
Modifications are incorporated into new design
8. Implementation -- the system is used in either a phased stage (cautiously) or in a big bang stage (at one go). The process of changing data from old to new is called 'conversion'
9. Maintenance and review -- a well-functioning and reliable system demands continuous review. (SDLC )
The image below illustrates each of these 8 steps as well as demonstrating the importance of the systems lifecycle to the database system:
(Systems Development Life Cycles http://azuliadesigns.com/system-development-life-cycles-sdlc/)
The database is the core component of the information system so database design is a part of systems development. The system development life cycle takes off from data design helping the researcher formulate an initial idea; conduct a feasibility study on this idea; analyze requirements for these ideas; and conduct a systems analysis of the program. This is furthered by the researcher coining specifications as a result of his systems analysis; implementing a Systems Design; going on to the Development stage of the process; and once again testing the system. The testing, if approved, runs into implementation of system; the maintenance of the system to keep it in working order; and a review. All of this leads back into initial idea to see whether the finished product and operation of this product coheres with original vision or whether it needs fine-tuning or a return to the drawing-board.
The database planning process incorporates some of the key elements of the systems life cycle as the following image shows:
(Designing…
