As we can see from the link above, i assume the development in the waterfall model will never end. As it reach the maintenance phase, the team will be need to re-analys the system or improve the system again. And what i to ask is it true that the waterfall cycle will never end (not have the point when the development will be end) as i assume before? Thank you in advance
The waterfall model is linear, so there's no cycling involved. When the product is built, the project is done. Your graph looks more like the Systems Development Live Cycle (SDLC) to me. The SDLC is used in process management to build, maintain and grow an IT system. So it has no defined ending.
Waterfall is done when the project is delivered into a Business-As-Usual (BAU) state.
One of the defining characteristics of a project is that it is Temporary. The other four are
- Causes change
- Uses a cross-functional team
- The deliverable is unique
- It causes uncertaintity
If you subscribe to this model then the project is technically done once a maintenance team takes custody of the deliverable to maintain it on an ongoing basis.
However, this method and definition are being challenged strongly by the rise of Development-Operations (DevOps) where the team that builds something also run that something using automation wherever possible. DevOps and Cloud and/or Microservices typically go hand in hand but it is not a rule.
It should be noted though that, despite the overwhelming number of posts on PM.SE, not all projects are IT or software related and thus, the waterfall model is still used worldwide and still requires a good grasp of its principles and techniques. There is no DevOps for building a railway or an Aircraft Carrier.