6. What are the principles of agile methods? 27. What are the Components of a Strong Value Proposition?

In a waterfall model, each phase must be completed fully before the next phase can begin. This type of software development model is basically used for the project which is small and there are no uncertain requirements. At the end of each phase, a review takes place to determine if the project is on the right path and whether or not to continue or discard the project.

Advantages of waterfall model

• 
  This model is simple and easy to understand and use.
  
• 
  It is easy to manage
  
• 
  Waterfall model works well for smaller projects where requirements are clearly defined and very well understood.
  

Disadvantages of waterfall model

• 
  High amounts of risk and uncertainty.
  
• 
  Not a good model for complex and object-oriented projects.
  
• 
  Poor model for long and ongoing projects.
  
• 
  Not suitable for high risk of
  

For example, in construction, these three general steps are usually followed:

1. 
   A building's physical design is created before any construction begins.
   
2. 
   The foundation is poured before the skeleton of a building is erected.
   
3. 
   The skeleton of the building is completed before the walls are built.
   

Phases of the waterfall model

When used for a software development process, the waterfall methodology has seven stages:
-Requirements. Potential requirements, deadlines and guidelines for the project are analyzed and placed into a formal requirements document, also called a functional specification.

1. 
   Analysis. This is also when financial and technical
   
2. 
   Design. technical design requirements, such as the programming language, hardware, data sources, architecture and services.
   
3. 
   Testing
   
4. 
   Maintenance. Corrective, adaptive and perfective maintenance is carried out indefinitely to improve, update and enhance the product and its functionality.