Solution:

An Operating System, as the various specific parts of the OS, could be developed as the user requires them.

A Graphical User Interface, like the OS, the GUI can be created according to the customer’s requirements and approval.

The waterfall model is amenable to projects that focus on the attributes such as data structures, software architecture, procedural detail, and interface characterization of objects.

A Web Application, a base application can be developed and delivered, followed by any number of additional plug-ins that the customer would want for additional functionality.

Three examples of software projects that would be amenable to the waterfall model are:

1. An adaption to accounting software that has been mandated because of changes to government regulations.

2. U.S. Department of Défense used the waterfall method in early technologies.

3. requirement definition, system and software design, implementation and system testing, and operational maintenance.