System development life cycle (SLDC)

The system development life cycle can be defined as a project management technique that divides complex projects into smaller, more manageable segments or phases. The SLDC is a framework defining tasks performed at each step in the software development process.

The life cycle defines a method used for improving the quality of software and the whole development process. It consists of a detailed plan describing how to design, build, test, implement, and maintain.

Computer systems are complex and often link multiple systems supplied by different software vendors. To manage this level of complexity, a number of SDLC models or methodologies have been created, such as waterfall, spiral, Agile software development, rapid prototyping, incremental, and synchronize and stabilize.

Objectives of SLDC

1. To ensure that high quality systems are delivered.
2. To provide strong management controls over the projects.
3. To maximize productivity of the systems staff.

Stages of System Development Life Cycle

System development life cycle consists of a set of steps or phases in which each phase of the SDLC uses the results of the previous one. The following are stages of system development life cycle

1. Preliminary study
2. Feasibility study
3. Investigative study
4. System analysis
5. Implementation
6. Maintenance
7. Study review

Explanation of each Stage

Preliminary study

Preliminary study is an initial exploration of issues related to a proposed quality review or evaluation.The aim of the preliminary study is to give an overview and ensure that the evaluation covers relevant areas of focus.

Feasibility study

A project feasibility study is a comprehensive report that examines in detail the five frames of analysis of a given project ir system. A feasibility study is an assessment of the practicality of a project or system. A feasibility study aims to objectively and rationally uncover the strengths and weaknesses of an existing business or proposed venture, opportunities and threats present in the natural environment.

Investigative study

This involves detailed study of various operations performed by a system and their relationships within and outside the system. During this process, data are collected on available files, decision points and transaction handled by the present system. Analyze and describe the costs and benefits of implementing the proposed changes. In the end, the ultimate decision on whether to leave the system as is, improve it, or develop a new system will be guided by this and the rest of the preliminary analysis data.

System analysis

System analysis is a process of collecting factual data, understanding the process involved, identifying problems and recommending feasible suggestions for improving the functional system.

System analysis can be broken down into five stages. they are :

• Scope Definition
  Clearly defined objectives and requirements necessary to meet a project's requirements as defined by its stakeholders
• Problem analysis :
  the process of understanding problems and needs and arriving at solutions that meet them
• Requirements analysis :
  determining the conditions that need to be met.
• Logical design :
  looking at the logical relationship among the objects.
• Decision analysis :
  making a final decision.

System Design

Based on the user requirements and the detailed analysis of the existing system, the new system is designed. This is the phase of system designing. It is the most crucial phase in the developments of a system. The basic study of system design is the understanding of component parts and their subsequent interaction with one another.

Implementation

After the user acceptance of the new system developed, the implementation phase begins. Implementation is the stage of a project during which theory is turned into practice. The major steps involved in this phase are:

1. Acquisition and Installation of Hardware and Software.
2. Conversion.
3. User Training.
4. Documentation.

Maintenance

Maintenance is done to eliminate errors in the system during working life and to tune the system to any variation in its working environments.

Study Review

Review activities occur several times throughout this phase. Each time the system is reviewed, one of three of the following decision will be made :

1. The system is operating as intended and meeting performance expectations.
2. The system is not operating as intended and needs corrections and modifications.
3. Users are/are not satisfied with the operation and performance of the system.