However, Stone left the company in 1899 and the idea was never implemented.

What I am seeing, his ideas are not being implemented.

"I'd like him to tell me how he plans to implement his ideas."

His idea to form a reserve force was later implemented.

However, his ambitious plans and ideas for the area were never implemented.

This idea, based on the model used in the Kentucky state budget, was never implemented.

If all your ideas were implemented, then why go down the pub like you say?

There had to be some way to ensure that its ideas were implemented.

Although extensively studied by various groups, such an idea has not yet been implemented.

Another similar proposal arose in 1840, though the idea was never implemented.