Wilson's perennial challenge is to make the balls identical - and durable, yet lively.

Although changes to the curriculum could be made quickly, acquisition of aircraft for the school remained a perennial challenge for the school's staff.

Finding room to store leftover seeds is a perennial challenge.

Parenting magazines, like wedding magazines, have the perennial challenge of finding new readers once the target audience stops feeling the need to subscribe.

When Ms. Christensen quit modeling this year, she faced the ex-model's perennial challenge: what next?

In recognition of this perennial challenge, the Container Store, a national 37-store chain, is sponsoring a series of "private college nights."

He is widely appreciated for his work as Mayor, especially in the area of flood control, a perennial challenge for city authorities.

Through the course of their correspondence, Boyd addressed many of the perennial intellectual challenges to the Christian faith, which led to his father's conversion.

The winner of a runoff next month would face a perennial challenge: completing his term.

These two aspects of unwanted vibration - internal and external - have been a perennial challenge to engineers.