I’d argue that one of the best systems to manage development is kanban in its purest form. Just the board, broken down into backlog, doing, and done — possibly with a sub column for ‘doing’ to represent “blocked”
For developers who run into snags, and can’t really nail down accurate estimates, it means all you need to do is break down tasks into manageable chunks, and work on one at a time. For managers organizing coordinated work effort with mercurial resources, it means a continual ability to communicate immediately to everyone what is most important to work on and to see where every one is at with work. And for customers with fickle requirements, they get to mess around with undone work as much as there’s like... might still turn out to be a shit project, but annoys everyone less in the process.
1. It’s dead simple
2. It can be constantly picked at without really affecting current work of development resources (assuming tasks are broken down into small enough units)
3. The state of the project can be quickly gauged at any time
4. Metrics can be generated with minimal (or no) disruption.
Where even kanban fails is that it is employed by people who feel an overwhelming need to tinker with it. No, we don’t need due dates on almost every single task. No, we don’t need complex software for it that takes 5 steps to create a ticket, where 2 would do. No we don’t need meetings about what we did... they can be 5 minutes and only need to address anyhing blocking us.
Everything else that people think they need from an organization system for development is either redundant, irrelevant, or is better suited to not belonging as part of a formal process that all parties need to adhere to.