SDLC (Software Development Life Cycle)

Reference: SDLC (Software Development Life Cycle) Phases, Process, Models

SDLC is a process that defines the various stages involved in the development of software for delivering a high-quality product. SDLC stages cover the complete life cycle of a software i.e. from inception to retirement of the product.

Adhering to the SDLC process leads to the development of the software in a systematic and disciplined manner.

SDLC Phases

1. Requirement Gathering and Analysis - During this phase, all the relevant information is collected from the customer to develop a product as per their expectation. Any ambiguities must be resolved in this phase only.

   Business analyst and Project Manager set up a meeting with the customer to gather all the information like what the customer wants to build, who will be the end-user, what is the purpose of the product. Before building a product a core understanding or knowledge of the product is very important.

   This step is importance to prevent scope creep

   Scope creep (also called requirement creep, or kitchen sink syndrome) in project management refers to changes, continuous or uncontrolled growth in a project's scope, at any point after the project begins. This can occur when the scope of a project is not properly defined, documented, or controlled.

2. Design - In this phase, the requirement gathered in the Software Requirements Specification (SRS) document is used as an input and software architecture that is used for implementing system development is derived.

3. Implementation or Coding - Implementation/Coding starts once the developer gets the Design document. The Software design is translated into source code. All the components of the software are implemented in this phase

4. Testing - Testing starts once the coding is complete and the modules are released for testing. In this phase, the developed software is tested thoroughly and any defects found are assigned to developers to get them fixed.

   Retesting, regression testing is done until the point at which the software is as per the customer’s expectation. Testers refer SRS document to make sure that the software is as per the customer’s standard.

5. Deployment - Once the product is tested, it is deployed in the production environment or first UAT (User Acceptance testing) is done depending on the customer expectation.

   In the case of UAT, a replica of the production environment is created and the customer along with the developers does the testing. If the customer finds the application as expected, then sign off is provided by the customer to go live.

6. Maintenance - After the deployment of a product on the production environment, maintenance of the product i.e. if any issue comes up and needs to be fixed or any enhancement is to be done is taken care by the developers.

Software Development Life Cycle Models

A software life cycle model is a descriptive representation of the software development cycle. SDLC models might have a different approach but the basic phases and activity remain the same for all the models.

• Waterfall Model
• V-Shaped Model
• Prototype Model
• Spiral Model
• Iterative Incremental Model
• Big Bang Model
• Agile Model

Conclusion

Adherence to a suitable life cycle is very important, for the successful completion of the Project. This, in turn, makes the management easier.

Different Software Development Life Cycle models have their own Pros and Cons. The best model for any Project can be determined by the factors like Requirement (whether it is clear or unclear), System Complexity, Size of the Project, Cost, Skill limitation, etc.

Example, in case of an unclear requirement, Spiral and Agile models are best to be used as the required change can be accommodated easily at any stage.

Waterfall model is a basic model and all the other SDLC models are based on that only.