During those long years in production, an animated film can undergo some significant changes.

The film spent several years in production and underwent many changes from the original concept, which was titled Drats!

The film underwent many changes and versions, resulting in an inflated budget.

The film underwent major personnel changes during its development stages.

After raising controversy for its subject material, the film underwent censorship and was finally released to commercial failure.

The film underwent a long post-production period suffering distribution problems.

The film underwent fourteen days of shooting and another four months of editing.

By the 1990s the film had undergone a complete critical reappraisal.

Also, during this time, the film underwent a major revision and got a new soundtrack.

Her films underwent a great deal of censorship in the Soviet Union.