While this isn't exactly scientific, in my experience working with managers over the last decade, people can turn on the charm if you will for 90 days.

Why does this matter?

If you don't have a clear understanding of success for a role, the proper plan for development and performance management, it's easy for low performers to keep hanging on. You've probably seen this at least once at a company where a problematic person seems to always fall under the radar. Maybe you've had the thought "how on earth does this person still have a job?"

Or what can happen too is what I like to call "hot potatoing" - passing a problematic team member around to another manager which just ultimately resets everything with each hot potato pass. I'm working with a company who has now passed someone like this to 3 different managers and this person's poor performance is wreaking havoc on the company.

Without that clarity, it's easy to fall into the trap of "oh they are doing great" in the two weeks following a performance conversation, writeup, or PIP. And that's wonderful, but they need to show consistency over a period of time. It can't be a sparkler situation where the performance is shining bright but only for a bit. People often shine the brightest right after a mistake is made.

For example, I just flew out of the Austin, Texas airport. A lot of people are nervous right now to fly out of there due to a recent near miss between a FedEx flight that was landing and a Southwest flight that was taking off. All due to a traffic control error. But I wasn't afraid. Why? Because I know that particular traffic control tower is on high alert after something so jarring. It's likely the safest time to ever flight out of Austin right now because that event shook people awake.

Now, what happens if the root cause of the incident isn't addressed - overworked team members due to understaffing, poor training, lack of engagement? That group will slide right back into the environment that led to the near miss in the first place.

In short, after we've messed up and it's been "exposed", we see high performance. But that isn't sustainable unless why the mistake happened in the first place is properly addressed.

So what to do as a manager? Get clear on why someone went off track, be clear in your feedback, create a long-term development path to effectively address the root cause and what the expectation is moving forward. Be realistic and don't let people "off the hook" until you have seen sustained performance instead of relying on the temporary, bright spot.

At the end of the day, one low performer and lack of accountability can damage your entire team. It takes only one drop of food coloring to dye an entire pitcher of water.