Placing blame doesn't seem appropriate or beneficial when working with teams. On the other hand, the management team's first instinct is to hold each other accountable.
What is an effective measure of dealing with mistakes ex post facto?
How or what methods are most effective in terms of proactively coaching the individual so the risk of reoccurance is minimized?
If your management team's first instinct is to start pointing fingers and assigning blame then quite frankly your management team is dysfunctional.
The best advice I can give you for dealing with a crisis, no matter what precipitated it:
FIX THE CURRENT PROBLEM.
I don't give a flying fart who caused it, and neither should anyone else at this stage: if something is broken, FIX IT. Worry about blame later.
Anyone standing around playing the blame game is less than worthless at this point. That especially includes management, who should make a concerted effort to stay the heck out of the way of the people who are actually trying to fix the problem.
Assuming you are a manager, your job right now is to keep everyone else out of your team's hair. Fixing a problem takes time. It takes 10 times longer if every layer of management between you and the CEO is hovering around asking how much longer.
Perform an honest, open post-mortem.
Determine why - more specifically determine The Five Whys.
Make sure you've found the root cause, and identify as many contributing causes as you can.
Develop a plan to prevent it from happening again.
Actually FOLLOW THROUGH on the plan you develop.
Too often the plan involves things like intensive cross-training, bringing in an expert to assess a particularly complex area, spending major money on infrastructure, etc. -- management is all for the solution until they see the price, or realize that resources (people) will be tied up and unavailable for billable work.
If you don't follow through on the plan to prevent reoccurrence you are dooming yourself.
Additionally your company should create a formal investigative process for the post-mortem tailored to the kind of work you do, which should include some form of documentation for the investigation and its conclusions so you can use them to refine your procedures/training in the future.
The Five Whys as already mentioned are a good component of that process, but they're only a starting point.
First off all, i think we are taking granted the term "Mistake" without definition. Don't make that mistake.
Poor management can cause mistake of all types including but not limited to:
a. Misunderstanding the task
b. Insufficient resources or situation to handle,
c. A communication gap (or lack of information)
d. Inadequacy of process
e. Lack of skill/training
f. Rare exception / first time events
g. Personal judgement errors
h. Personal goof-up
When something goes wrong, it is time to learn.
First off, instead of assuming anything, get to a senior who is the authority. Explain everything as is. Put the facts in right (unbaised) order - and ensure that you supply proper data to backup.
Listen to your senior about what is the scheme of things under his mind, and how you could have done it right in the same situation. Ensure that everyone is in agreement as to what is the real reason of what went wrong. [This is easier said than done!]
Clearly make a plan for how to correct the current mess.
Submit your apology (even formally if needed) to all concerned (but only those who concerned)
Learn from the mistake and move on.
Overall, in case of all incidents, we must focus on what is wrong, why it went wrong and what to do now. You should never go personal about a tech/process/business issues.
First off, it can be very important to realize that what you perceive as mistakes may be viewed (by those committing them) as rationalized acceptable behavior. Therefore, directly confronting individuals who've made mistakes can be... counter-productive.
What is an effective measure of dealing with mistakes post de facto?
Before anything else, set about fixing it. The more time you waste in allowing mistakes to fester, the more damaging they are. If you're the supervisor, this is your job; if you're not, this is your opportunity to prove you're capable. How precisely you manage a mistake is dependent upon the mistake. However you do it, make sure that your attitude is that of "I do this for the team" not "Somebody had to clean up his mess".
How or what methods are most effective in terms of proactively coaching the individual so the risk of reoccurance is minimized?
"You can lead a horse to water, but you can't it drink." Lead by example; if you demonstrate how to do it right, trust that the group will look to you for guidance in the future. If they don't, someone needs to go – unfortunately, if the problem is constant despite your best efforts, that someone may be you.
Being direct is, again, counter-productive; you'll come across as a know-it-all and alienate the rest of the team. However, being the paragon of the team will inspire and lead your team to new heights. To do this, you have to show them that:
You're working to move up in the world, and, presumably, keep your job. Being humble and showing that you know the right way to do the job isn't just the sign of being a good worker, but a good leader.
I want to approach this from a different perspective. I think the other answers have covered well what you do when there is a major mistake particulaly when complex processes are involved.
However, not all mistakes are process driven. People still do the work and people make mistakes that are based on several things:
These are often not the kind of mistakes that drive the need for a massive effort to do post-mortem analysis. But they do drive the need to deal with the individual who is making more than the occasional mistake.
So let's deal with some of those possibilities. I'm going to lump incompetence and carelessness together as the process to deal with them is similar. First, explain to the person, what was wrong, why it was wrong and how to do it correctly. Then make the person make the fix. If they learn from this and don't continue to make the same mistake, then that's all that is needed.
But people being people, this won't fix everyone. Some people will need private counseling about their problems and why they keep making them and may need to be put formally on a plan to fix their lack of skill or caring about the quality of their work. This needs to be a plan with consequences. If the person doesn't shape up after giving several chances to fix the problems they have, then you may need to let them go. And they need to know this is a possibility if they don't fix what is wrong. It should never come as a surprise if you are getting let go for lack of performance. But that first talk shouldn't be the kiss of death either, if the person straightens up and improves, it should be possible to come off the performance improvement plan and be treated the same as the other employees.
Now in the processing of the private discussions to find out why the mistakes are happening, you may find that distraction, exhaustion, or personal stress are involved. If distraction is causing a problem, then as a manager, you need to fix whatever is causing the distraction. That might mean not expecting the person to multitask, it might mean moving to a quieter location, it might mean having someone else handle technical questions or help desk calls or what ever is the thing that keeps pulling the person off task. Then see if performance improves.
If exhaustion is involved (and is work-related), the manager probably is the one who made the mistake and should have noticed that the person was working too many hours. If the person is working more than 8 hours in a day, send him home and tell him not to come back until he has slept a full night. Then stop planning tasks so that they require more than 40 hours a week. Employee exhaustion is often the result of management errors. So take the blame and fix the problem. Now sometimes an employee is exhausted due to other issues outside of work and those will come under the next paragragh discussing personal stresses.
If the person tells you of outside reasons why he is making mistakes, then you need to assess those reasons and come up with a plan to mitigate them. Sometimes this means a short-term lightening of the load (as was done for me when my beloved died), sometimes it might mean moving to a less stressful position permanently (in the case of someone who will be under the stress for a long time, such as when somone has become a caregiver), it may mean checking their work more frequently. It might mean a change of schedule. It might mean putting him on medical leave or short term disability or part-time hours. It may mean telling him to quit that second job or requiring they get medical treatment for depression or insomnia or a whole host of other things.
Anytime you need to go one step up from just having the talk about the mistake and how to fix it or the identification of a personal stressor that is affecting work that can't be fixed by a simple short-term rearrangement of work, you may need to get HR involved before you deal with the person directly. They are aware both of legal issues you may not be aware of and of possible resources (as well as ways and means as to how to do somthing like put someone on short-term disability) and company policies you need to follow. They are the manager's friend when there is serious performance problem that needs to be addressed.
Humor and Patience.
That is, wait a while. Maybe some weeks. Then when things are relaxed mention it in a group setting as a joke, e.g. 'Yeah, well we all know what happens when we [follow bad practice x], from when we saw effect y right... ha ha'. Note you're not even mentioning the persons name, but ina group setting folk have a chance to agree or refute you.
