Sometimes there are almost too many things going on at work to keep it all straight. Is it fair to assume everyone on the team will get everything right? I say no. Many people you may only see at work, so sometimes it's easy to forget that they have lives outside of work. They have kids, hobbies, or other things that distract them at time. Now how can you determine when a mistake is just human error or when it truly is a problem? In projects, you need to compensate for mistake by having the right systems in place. If someone accidentally did something to bring down the Microsoft corporate homepage, sure you may be able to chalk it up to human error. But the question I would ask is why aren't there checks-and-balances in place to catch that human error before it becomes catastrophic? Human error follows us everywhere we go. And in the software industry, we actually code for it. We figure out what the customer may do that isn't appropriate for how a feature should be used and try to lead the customer back to the common path. That assumption is based on the fact that people using your software also have human error. It's just a natural part of everything we do. It's interesting to think that in testing you are trying to emulate human error much of the time.
But let's go back to team members with too much going on to keep it all straight. There's a rule that I follow to help me determine when a mistake is human error or when a mistake is really a problem. If someone on my team does one thing wrong, it's a mistake. If it happens a second time, I take note. At the point it happens a third time, it has become a trend. At that point, it gets identified as a weakness or area of improvement and gets tracked a lot closer. The person also receives more feedback and coaching on how to fix it than they did before when it was just a mistake. To give more context on these "mistakes" here are some examples:
Someone who yells in meetings - once may just be because of a bad day, three times and it's become a problem
Someone states they will get something done and then you don't hear back from them - one time and it may have fallen lower on their priority list, three times and they either have a problem with following up or with communicating.
I've seen managers that can't handle the human error element. They instill fear in their people that mistakes are unacceptable. This leads to a higher level of stress across the team and people actually become more prone to mistakes. So I stick very close to this rule of 3 times becomes a trend. It helps to remove the emotional part of making mistakes. Most people feel bad when they make a mistake, so they can be held accountable for their mistake. But beyond a quick discussion and their awareness that it was a noticeable mistake, I usually don't see another one. But I always look out for that trend. Are you?