waterfall model | software engineering |

There are different types of software development lifecycle SDLC models. The first one is the waterfall model. Here in the waterfall model you are having different phases like requirement analysis. system design, implementation, testing, deployment and maintenance.  Waterfall model is the first software development lifecycle model to be used widely in software engineering to ensure the success of the project. So almost all the software engineer use this waterfall model. The whole process of software development SDLC is split into separate phases. If any process is there if any product is there or  if any problem is there that problem is divided into series of phases.The outcome of one phase acts as an input to the other phase. The outcome of requirement analysis acts to the input to system design. The out come of system design act as an input to implementation. The outcome of implementation is input to testing. The out come of  testing is input to deployment. Outcome of deployment is input to maintenance. This is the process in which outcome of one phases acts as an input for the next phase tha

Now one thing you have to remember that if one phase is completed then only you can go for the next phase. Before the completion of first phase you are not supposed to go for the next phase. Once it is freeze then go for the next phase. We have to follow the sequence that's why we call it as a waterfall model. if you drop the water the stages will be changing from high to low. Whenever we are pouring a water from high level it is coming down. So like that it has to flow like that. 

1. Now first see the requirement analysis what do you mean by this requirement. Here the requirement gathered and documented in a requirement specification document. So whatever the users requirements suppose I am saying to the person means I want that these are the specifications. I need the output like this I want the product like this I am going to run an app like this. So you are giving some specification and ideas to the team people. You call it as a requirement analysis that will be written in a document and they are saved. So whatever the user requirement and what are the customer requirements that will be first documented after that the system design.
2. The system design helps in specifying hardware and the system requirements and also defining overall system architecture. It means what type of hardware we have to use and whatever the requirements that we need and also defining overall system architecture to develop a complete system. Whatever they need that you call it as a system design. 
3. Next they go for the implementation.So in the implementation with input from system design so whatever the input that we are taken from the system design. The system is developed and divided into small programs called units. So here we are implementing the program into small units. Each unit is tested for its functionality and it's referred as unit testing means we are writing it and we are testing that each unit by using unit testing. So that everything will become and they under the implementation. Now product is over and it is every unit. Small programs are tested and it is easy to successfully test the small programs. So that will be checking in this testing after that deployment.
4.  okay so in testing here you can also call it as integration testing. So each unit we are testing after that you have to combine all units that you call it as integration. All units are integrated and tested for any faults and failures.
5. The deployment is nothing but once the functional and non-functional testing is done and project is completely fit then you are ready to deliver the product to the customer environment or you directly releasing into the market that stage you call it as deployment. Now released everything and my product is now running in the market and my customer is using so even though if your project is over your product was delivered if any issues come up from the client environment you have to be fixed those problems. And also if they want any enhancement to that product you have to add that and you have to release it again that stage you call it as a maintenance.
6. So the maintenance stage will be occurred in the customer environment. Maintenance stage will be done on the customer environment so if issues comes in the client environment those will be fixed. You call it as maintenance. 
   

 

so these are the different stages in the waterfall model so these are all the advantages of using the waterfall model.

Disadvantages of water fall model

Now let us see the disadvantages. The disadvantages in using the waterfall model is no working software is produced until late during the lifecycle that in one and the next. So if you follow the waterfall model if a problem came across and the high amount of risk and uncertainty will be there. High amount of risk and uncertainty will be there in whatever model and it is not good model for complex and object oriented programs. This is a poor model for very large and ongoing projects. These are the advantages and disadvantages of using the waterfall model.Requirements, system design, implementation, integration interesting, deployment and the maintenance. Now let us see the advantages and disadvantages of using a what a fall model. 

Advantages

First thing it is simple and easy to understand. and It is easy to manage. Each phase has specific delivery and review for process for next phases and completed one at a time. So means once if one phase is completed then only you are supposed to go for the next.