The Waterfall model is a product development methodology that enables tasks to be addressed in a sequential plan without returning to previous stages.​

Advantages of the Waterfall Model

1) Precise and Detailed Work Plan

   This is the system's main advantage: during the analysis phase, all processes are thoroughly examined, potential risks are considered, 
   and responsibilities are assigned. Every activity is well-thought-out and documented, leaving performers to simply follow the plan.

2) Understanding of Deadlines and Budget Costs

   Alongside work stages, financial costs required by the team are calculated. This is convenient for both performers and clients, reducing the risk 
   of unexpected expenses. The project's completion date is also known in advance; only force majeure can affect it.

3) No Costs for Internal Team Communication

   Performers don't need to delve into the work process from scratch—it's sufficient to carry out actions according to the plan. This is important, 
   for example, when new people join the team.

Disadvantages of the Waterfall Model

1) The System Is Not Ready to Be Flexible

   The main issue is that it's impossible to predict all project complexities in advance. Suppose an error discovered during the development 
   or testing phase poses a risk of completely halting work and starting over. This results in wasted time and money.

2) The Client Is Not Involved in the Development and Testing Phases

   The project customer is presented only with the final result, which they may or may not accept. Sometimes, comments are needed in the middle 
   of the work.