• It gives developers an opportunity to deliver value to the consumer faster.

Let's see what approaches also exist in the world of software development besides the agile approach. First of all, this is the previously mentioned cascade methodology, also called "waterfall". We have already learned that in 1970 Dr. Winston Royce defined Waterfall methodology and suggested its basic principles:

• Program design comes first. Program designers work on the design of the system, not developers. Designers allocate e data processing models: database scheme, resources, some kind of non-functional requirements, interface, etc. Then an overview document must be prepared. The document should be understandable, informative, and current. Each team member must have an understanding of the system, and at least one person must have a deep understanding.

• Document the design. Some (in fact most) developers may wonder how much documentation is needed. Royce gives a simple answer: “Quite a lot”. Moreover, he says: “If the documentation is in serious default, my first recommendation is simple. Replace the project management. Stop all activities not related to documentation. Bring the documentation up to acceptable standards.”

Why documentation is important? Royce gives some points:

• documentation is a way of effective communication;

• during the early phase, the documentation is the specification and is the design;

• during the testing phase, the documentation can be considered as acceptance criteria;

• the documentation help newcomers to understand the system better.

• Do it twice. If your system is original, you want to verify your ideas or concept. Royce recommends creating some kind of MVP (Minimum Viable Product)11 of your product to check the ideas. Then, the second version of your product will be finally delivered. The first version may not be provided to final customers/users, but stakeholders12 want to see a prototype of the product. It may lead to requirement changes, and it is an effective way of the development process. The final version of the product will be closer to market needs.

• Plan, control, and monitor testing. Testing is one of the most important phases of the SDLC (Software Development Life Cycle)13. You check your ideas and concepts, verify implemented system comparing it with system design. Royce recommends inviting the other persons to verify your system. He says that it would be more effective to give a big part of the testing to people who did not contribute to the system during the previous phases. The documentation will help them to test the system better.

• Involve the customer. Your project customer and stakeholders should be involved in all phases of the development. They will help to design and implement a system that will meet their needs closer. Moreover, the stakeholder may change their opinion about the system and give new requirements. As a Project Manager you should meet the changes with pleasure because after all your customer will be satisfied.

Waterfall is based on a logical sequence of steps that must be taken throughout the software development lifecycle. Each stage is coordinated by competent employees, documented and passed on.

Although the popularity of the Waterfall model has waned in recent years, but the nature of the sequential process used in the waterfall method is intuitively close to developers.

The model proposed by Dr. Royce is extremely simple and clear. It consists of several blocks, each of them covers its own area of responsibility.