SDLC

SDLC phases
1. Preliminary Analysis: The objective of phase 1 is to conduct a preliminary analysis, propose alternative solutions, describe costs and benefits and submit a preliminary plan with recommendations.
The 1st stage of SDLC is the investigation phase (Feasibility study). During this stage, business opportunities and problems are identified, and information technology solutions are discussed. Multiple alternative projects may be suggested and their feasibility analyzed. Operational feasibility is assessed, and it is determined whether or not the project fits with the current business environment, and to what degree it addresses business objectives. In addition, an economic feasibility investigation is conducted to judge the costs and benefits of the project. Technical feasibility must also be analyzed to determine if the available hardware and software resources are sufficient to meet expected specifications. A legal feasibility study is important to discover any potential legal ramification. The results of the feasibility study can then be compiled into a report, along with preliminary specifications. When the investigation stage ends, a decision whether or not to move forward with the project should be made. If it is decided to move ahead, a proposal should have been produced that outlines the general specifications of the project.
Conduct the preliminary analysis: in this step, you need to find out the organization's objectives and the nature and scope of the problem under study. Even if a problem refers only to a small segment of the organization itself then you need to find out what the objectives of the organization itself are. Then you need to see how the problem being studied fits in with them.
Propose alternative solutions: In digging into the organization's objectives and specific problems, you may have already covered some solutions. Alternate proposals may come from interviewing employees, clients , suppliers, and/or consultants. You can also study what competitors are doing. With this data, you will have three choices: leave the system as is, improve it, or develop a new system.
Goal of this phase is to prepare BRS (Business Resource specification) or URS (User Resource specification) or CRS (Customer Resource specification). It is good practice if BRS is prepared by company owner that describes what is his business, so analyst can decide and suggest appropriate solution for the business.
Describe the costs and benefits.

2. Systems analysis, requirements definition: Defines project goals into defined functions and operation of the intended application. Analyzes end-user information needs.
Goal of this phase is to prepare SRS (System Requirement Specification).

3. Systems design: Describes desired features and operations in detail, including screen layouts, business rules, process diagrams, pseudo-code and other documentation.
Goal of this phase is to prepare HLD (High Level Document) / Architectural Design and LLD (Low Level Design).

4. Development: The real code is written here. Goal of this phase is to prepare code for divided modules and unit testing (N unit).

5. Integration and testing: Brings all the pieces together into a special testing environment, then checks for errors, bugs and interoperability. Goal of this phase is to integrate different prepared modules from coding phase and testing of integrated module (Product).

6. Acceptance, installation, deployment: The final stage of initial development, where the software is put into production and runs actual business.

7. Maintenance: What happens during the rest of the software's life: changes, correction, additions, moves to a different computing platform and more. This is often the longest of the stages.

Waterfall Model

V & V - Validation and Varification