What are some {desirable} and {effective} strategies for...

What are some {desirable} and {effective} strategies for ensuring that a performance improvement plan is {successful} and leads to {significant} improvement for an employee who has {been with the company for a considerable} {period of time}, taking into account their {relevant} skills, {strong} motivation, and {supportive} work environment, and how can I {implement} these strategies to ensure that they are {beneficial}, {efficient}, and {suitable} for this particular employee?