Systems Life Cycle and Database Systems

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 ensure it meets specifications

7. 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:

(://www2.amk.fi/digma.fi/www.amk.fi/opintojaksot/0303011/1142845462205/1142847774995/1142849037295/1143037341377.html)

What we have here is Database planning — the initial idea. We also have implementation, testing, and monitoring with the loop-back process of analysis and design. The core steps are similar. Life systems elaborate on these. In life systems too, the process loops back to initial idea to make sure that the ultimate coheres with original.

In both cases, the mission objective and scope and boundaries as well as expectations of the database system have to be defined in order that developers know what they are intending to build.

It is precisely for this reason that the incorporation of life systems is so important — if not crucial — to the structuring of the database system. The developers need a blueprint to guide them. They need something to map out for them every step of the way and, each step of the way, they need to compare the construction to the initial idea in order to decide whether to retract and modify or whether to continue. The life systems plan provides this.

By incorporating the life systems plan, too, the producers are forced to clearly define expectations, challenges, and objectives and to see these requirements from various perspectives. Each stage, too, stands differentiated by itself so at the completion of one and before embarking onto the other, developers of the system have a chance to review and assess whether the task matches original idea.

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 organization that I am thinking of uses a hybrid mechanism that incorporates the original waterfall model; rapid application development (RAD); joint application development (JAD); the fountain model; the spiral model; build and fix; and synchronize-and-stabilize into one whole methodology. This is effective since each SDLC has its own strong points advantages, tools and so forth. David Christiansen (for instance) encourages companies to embrace a variety of systems.

As regards my own company, it is a small one so therefore it is important that the system be one that is constant through the unit and mirrors its goals.

Chrisitanion advises that some of the questions asked about the system used should include the following:

Is the software better? Is the team more productive? Is it easier to attract and retain good employees? Is your company more competitive because everyone does everything the same way? Do concepts move to products more quickly? Does your stock price go up?

This will help the company select a system that coheres to its goals, organizational structure, and operation.

In a larger company, it is important for each division to have slightly different software development life cycles since the goals and manner of acting as well as behavior and task of each are different and the SDLC needs to simulate and help the different divisions accomplish these tasks. A diversity of approaches to software development is healthy in a large company since it allows room for freedom and reflects the inherent diversity of the company. A small company however will not only squander money on but will also create conflict rather than consistency and creativity. (Techtarget.com)

Sources

Techtarget.com Varying SDLC methodologies among ://searchsoftwarequality.techtarget.com/answer/Varying-SDLC-methodologies-among-development-teams

SDLC

http://azuliadesigns.com/system-development-life-cycles-sdlc/