The father of the crystal clear process is Alistair Cockburn. Crystal clear, like the other agile processes, is rooted in iterative-incremental development. Alistair’s work is also heavily focused on humans, invention, and the idea of developing software as a corporate game. Interesting in this process is the emphasis of product and methodology fine-tuning at the beginning and in the middle of the iteration. This approach enables every project to evolve not only the system deliverables but also the chosen process itself. The ceremony of project documentation is also delegated to the project level.
Crystal clear also requires the team members to be in close proximity, the identification of real users, and that the team use basic code-versioning tooling. A major differentiator from other processes is the consideration of project communication. The larger the team, the more communication has to be factored in. Whereas a team of 5 or 10 members might easily fit into a team room with very effective communication channels, this setup might not be applicable for a team of 50 or more members. Based on the size of the team, different flavors of the crystal clear family can be adopted.