The implementation or creation of each system requires a specific project.
Each project is the involvement of people with the right qualifications for a some time.
the success of the project depends on the efficiency of organizing these people.
Each project can be compared to a game of chess.
At the beginning the two players have the same resources and the same time.
The one who better use his resources will win.

Each project consists of the parts. Each part consists of the tasks.
The ability to define and engage resources within the specified time
is necessary to bring the project to the end.

It is often difficult to implement all elements of the project.
It is important to organize tasks by specific priorities
and concentrate on the most necessary elements.
In the case of "e-shop" orders must work properly.
Lack of sophisticated graphics does't prevent activity.
Elements less needed can be developed at a later time.

Each project requires a certain trade-offs between time, resources and scope of the project.
We need to determine what is most important. If the the scope is most important
in case of an emergency project we need to increase the resources or time.