Hello followers! I hope you are enjoying the Raising and Giving week as much as I do :)
Last week I was writing about system analysis and design, and information systems components. Today I will explain what a System Development Life Cycle (acronym SDLC) is and its stages.
In order to develop a system you must arrange tasks into phases (groups of activities), involve users for whom the system is being built and develop procedures the company would like to have in place for their employees to follow.
System Development Life Cycle – It is a process of creating information systems, and the models and methodologies that people use to develop these systems. The SDLC process was designed to ensure that end-state solutions meet user requirements in support of business strategic goals and objectives. SDLC is used to develop, maintain and replace Information System. Systems are so big and complex that teams of architects, analysts, programmers, testers and users must work together to create the millions of lines of custom-written code that drive enterprises. SDLC is used to correct problems in existing system, and to improve the system quality and structure. It certainly eases the process of building a system and helps reduce failures such as unclear objectives, possibility of not meeting user needs, or cost overruns. The most important part in SDLC is communication. Without good communication it is not possible to satisfy the customer, and that may lead to errors and omissions which can be expensive in the end.
SDLC has five stages:
1. Planning – this phase begins after the project has been defined and appropriate resources have been committed. The first part of this phase involves collecting, defining and validating functional, support and training requirements. The second portion is developing initial life cycle management plans, including project planning, project management, Configuration Management (CM), support, operations, and training management. We cannot just go and build the system.
2. Analysis – system requirements are studied and structured in this phase. System analysts collect facts from existing system users in order to develop limitations and details. They will also define new system objectives. They use different data gathering techniques such as interviews, observations and surveys. This is an attempt to understand all aspects of the current system and eventually indicate how things may be improved by a new system.
3. Design – Describes how the system will fulfil the user requirements. To achieve this, logical and physical design must be created. The logical design produced during the analysis is turned into a physical design – a detailed description of what is needed to solve original problem. Input, output, databases, forms, codification schemes and processing specifications are drawn up in detail. In the design stage, the programming language and the hardware and software platform in which the new system will run are also decided. Data structure, control process, equipment source, workload and limitation of the system, Interface, documentation, training, procedures of using the system, taking backups and staffing requirement are decided at this stage.
4. Implementation – this is followed by testing and then implementation. During this phase, the new or enhanced system is installed in the production environment, users are trained, data is converted, the system is turned over to the sponsor, and business processes are evaluated. This stage includes efforts required to implement, resolve system problems identified during the implementation process, and plan for sustainment.Coding - the physical design specifications are turned into working computer code. Integration and Testing- a testing environment is created where all components are brought together. Installation - here the new system is rolled out.
5. Maintenance – After having the user acceptance of the new system developed, the implementation phase arises. Implementation is the stage of a project during which theory is turned into practice. The major steps involved in this phase are:
Acquisition and Installation of Hardware and Software
The hardware and the relevant software required for running the system must be made fully operational before implementation. The conversion is also one of the most critical and expensive activities in the system development life cycle. The data from the old system needs to be converted to operate in the new format of the newly developed system. The database needs to be set-up with security and recovery procedures fully defined. Bugs must be rectified and requested changes completed.
Have a look at this interesting video introducing a Database Design:
Instructor Cathal Doyle