Every week in my consulting work advising senior executives on the people side of the business equation, someone invariably will tell me about a colleague or employee doing something that ticks them off.  And, I will ask, “Did you talk to them about it?  More often than not, they will respond, “Not yet, or, Nope, and I probably won’t.”  And I will then ask, “Why not?”  The most frequent answers circle around the following: “it won’t do any good,” or, “it’s more trouble than it’s worth,” or “the risk of it going sideways is worse than letting it go.”

I agree, it’s dicey having a conversation with another person about something they did that is a problem for you.  And, sometimes we do have to make a risk/reward assessment that might end up in not taking any direct assertive action… for the time being.  But, if you conclude that it’s necessary and important that you do something assertive about it, there are a few steps you can follow to increase the likelihood that the conversation will be constructive.

1. Start with yourself.  Get yourself centered by assuming that the other person is not consciously trying to tick you off.  Most people don’t wake up thinking, “How can I annoy my colleagues today?”  There are a few narcissists and sociopaths who wake up thinking about ways to get the upper hand but, for the most part, most people (99% – my unscientific guess) go to work just wanting to do a good job.  We call this: “assuming positive intent.”  By assuming positive intent, you are more likely to listen well and respond more productively because you won’t be expecting or assuming the worse.  You will be less emotionally worked up and therefore, less likely to be primed to go on the attack.
2. Get your ducks in order so that you don’t shoot from the hip.  Think about what you want to discuss (the issue) and write it down.  Describe the behavior that is annoying and the impact it has on you or others.  Stick to observable facts. 
3. Don’t try to psychoanalyze the person. Do not attempt to provide any semblance of, “I think you do x because of y.”  No one wants to hear your attempt at mindreading or being an amateur psychologist (it is condescending and patronizing at best).  It’s the quickest way to shut down a conversation.   Just stick to observable facts. 
4. Then, when you have the facts laid out in writing that you can refer to during the conversation (under stress we forget).  Make an appointment with the other person to ensure they can give the necessary time and attention to talk with you.  Don’t spring this on someone.  Ask them, “Can I schedule some time with you to discuss an issue that is bothering me that I hope to resolve?   You want them psychologically/emotionally ready to listen. 
5. Extend an olive branch and give the person some wiggle room to save face.  When you do meet with them start off with an olive branch.  Saying something like, “There has been some issues that have arisen between us that are concerning to me which you probably don’t know have happened and I am sure you didn’t intend to happen.  I want to discuss this with you because I think it’s important to clear the air and resolve so that we can work better together.” 
6. Then outline the issues as a “problem statement” rather than an accusation.  Say something like: “Over the past couple of weeks X happened on 3 occasions.  (Describe the actual event/behavior without offering any attempt to make sense of it).  I don’t know why it keeps happening, but it has made it difficult for me to do Y.  Do you have any thoughts about this that we can discuss to see if we can get back on track?”
7. Then let the person respond without interrupting or debating.  Ask only clarifying questions.  Don’t debate or dispute.
8. Then summarize your understanding of what they said and ask, “Did I summarize that accurately?”  If they say yes, then proceed to step 9 if they say no, then ask.  “Where did I misunderstand?”  Keep this going until they say, “Yes, you understood me accurately.” 
9. Then say something like, “I can understand from your perspective how you see things that way.  Are you open to hearing my take on this?”  You do this to create and openness on their part to hear your side of the equation.  Sounds simplistic but, when someone says, ‘Yes, I am open to hearing your perspective.”  They will be much more open to listening and trying to reach a solution than if you just barreled ahead and told them how you feel.  And, even though you are acknowledging their perspective it does not mean you agree with it.  But you will reduce the resistance to hearing your side when they feel you’ve listened fully to their side.  I call this the Aikido (martial arts) approach to resolving interpersonal problems.  You don’t attack but allow the other to come at you while stepping aside offering no resistance, allowing them to fall past you.
10. Once you outline your side of the equation, you will, hopefully, be able to say something like, “Can we put our heads together and figure out a way to make this work better in the future?”
11. When you are done be sure to thank the person for being willing to work with you on this.  It always pays to reward constructive behavior.

The odds are that if you get to step 10… you will be able to put into place some corrective changes that you both agree to.  Then, be sure to uphold your end of the bargain and keep your fingers crossed that they will too.  Otherwise, you will need to do this again but with even more ammunition next time.  And, if you try this a couple times with someone and they keep dropping the ball when you escalate this to your boss, you can honestly say you tried to resolve this on your own.  No boss wants to get sucked into resolving conflict if the warring parties haven’t first tried to resolve it themselves.  As one of my CEO clients once told two warring executives, “I pay you way too much to have to be your referee. Figure out how to work together better or you will be looking for another job.”