How do you write a letter of reprimand on a supervisor who constantly causes confusion among other supervisors?

Reprimanding a supervisor or any other internal staff member, is a process, not just one letter.

Step one is speaking to the supervisor; outlining the problem and communicating the accepted standard. If there is a written policy in place that covers the specific situation, that should be provided to the employee at that time. The employee should be advised to ask for help in how to handle any situation that they are unsure of what is appropriate for the circumstances. The employee should be given the opportunity to correct their behavior on their own. In many cases this step will be the only action necessary.

Only if the employee continues the unacceptable behavior will a written notification be necessary. The letter should mention the previous conversation, mention the written policy provided (if applicable), and include the date of the conversation. The letter should repeat the policy stating what behavior is appropriate, give a time period with a deadline date that the situation will be reviewed with the employee again. The letter should be simple, to the point, without any personal attacks or derogatory language. A sample standard business letter format can be found on the link below.

At the time of the given deadline date, the employee's behavior should be reviewed in person. If the employee has shown progress and needs more time, then a new deadline date can be set. Further interaction with the employee may give you both the opportunity to further strengthen and support the behavior that is acceptable. If no improvement has been made, this meeting can be followed up with a dismissal letter citing the steps taken up to this point.

A supervisor or any employee should be given an opportunity to grow and develop; or to show that they aren't able to learn.