As I was moonlighting as a manufacturing supervisor an interesting issue came up. Often times union contracts will have supposed "deadly sins" usually there is a number associated with them i.e. 8 deadly sins (we have 12 I think). Supposedly these are violations of company policy, law, or simple good conduct that would not have a requirement for progressive discipline. Usually fighting on company property and harassment are on there as well as others depending on your company culture.
There is a fine line between being a jerk and harassing people. I am not sure many people would even be able to define where that line is. My definition is when a person's behavior creates an intolerable/unsafe/hostile environment for another employee. When someone has been talked to about being a jerk to more than one person, it should shoot up red flags in supervisors minds. Maybe he gets one get out of jail free card (they should still record the incident though), moves and acts like a jerk so much that again it is brought up to a supervisor. Now, I would say you probably have harassment of some sort going on. When you throw in employees moving to different shifts or crews this can become infinitely more complicated. Honestly, I would hate to tell supervisors to not use disciplinary discretion with their employees. If supervisors believe it is a one time thing or just a bad mix of personalities I can see some coaching going on to fix the situation. However, if it happens over and over with different supervisors you are asking for trouble as an organization in the form of broad harassment claims from multiple people.
So there you go blue collar supervisors. Some form of documentation allows your brethren to put the pieces together later if they need to while no documentation may keep a jerk on the job longer than necassary. I personally like problem discussion forms. They also help organize your thoughts before you talk to the employee. Get over the fear of "putting something in his/her file". In the end that is what it is there for...to tell you the past of the employee. In other words CYA.