Since then the design has undergone almost continuous refinement and a succession of model numbers.
On January 4, 2012, the paper's design underwent a complete overhaul.
The design, particularly the engine, has undergone several radical changes.
The design of the engine had undergone numerous changes.
The design has undergone some minor changes compared with the prototype.
The accepted design may undergo several rounds of modification before entering the production process.
And the design underwent changes even after the premiere.
The M.52's design underwent many changes during development due to the uncertain nature of the task.
Krusty's design has undergone several subtle changes since the early years.
Also throughout the years, the design of the ergonomic grips underwent several changes.