What is a post-mortem?

A smart man learns from his mistakes.
A wise man learns from the mistakes of others.

1. Introduction

The term post-mortem is latin for "after death", and originally referred to a medical examination of a corpse to determine the cause of death. The term has, more colloquially come to refer to any "after the fact" analysis and discussion of a recently completed process or event, to see what lessons we can learn from it.

Such analyses are have been going on for a very long time. Five thousand years ago Egyptian doctors recorded wounds, treatments and results to build up a body of knowledge about what did and did not work. During the middle ages, engineers from all over europe would flock to the site of a collapsed cathedral to attempt to learn lessons that would prevent similar fates from befalling their own cathedrals. Military strategists have long studied every battle ever recorded to see what lessons they could learn.

In organizations that are serious about learning from their mistakes, and getting better at their jobs, post-mortems are a schedule part of every project.

2. Goals of a Post Mortem

The goals of a post mortem review are very simple:

• To identify the things we did right, so that we can remember to try them again in similar situations.
• To note the things that should have been done differently, so that we can refine our techniques in the future.
• To note the things that we did wrong, and to suggest alternative approaches or safety measures that we should employ the next time we face a similar problem.

Exploring what we did wrong is frightening ... and in some organizations it is dangerous. If admitting having made mistakes opens us to criticism or discipline, we are unlikely to make such admissions. This strategy is ultimately self-defeating, since failing to understand a past mistake usually condemns us to repeating it again in the future. Organizations that are serious about improvement understand this, and take trouble to create a process and culture wherein it is safe to explore mistakes.

When we enter into a post-mortem process, we must all accept a few basic premises:

• Everybody tries to do their best, as best they understand it.
• We make our decisions in stressed situations, with imperfect information.
• We are often called upon to carry out tasks for which we have not been trained, with what-ever tools and resources happened to be at hand.
• Mistakes are inevitable in such situations.
• The goal of this process is not to find fault with any individual or their actions. Rather it is to look at what happened and see what lessons we can learn from it.
• The output of this process will not be an assessment of any person or group of people, but rather an assessment of our processes, and how they can be improved.

It is absolutely essential that everyone involved completely accept this "no blame, we are here to learn model". Many organizations go to great trouble to create such safe environments. The FAA, for instance, has an Aviation Safety Reporting System, whereby pilots who make "mistakes" can gain immunity from regulatory discipline if they report those incidents to the ASRS.

3. Process of a Post Mortem

In highly stressed environments, built up fear and anger may make it very difficult to get people to discuss (or even to objectively look at) a recent project. In situations like this, the organization may be in serious need of healing, and it may be necessary to have the process managed by a professional facilitator. Another of the assigned readings describes such a process. In healthier settings, it may be "just another meeting" where the goal is simply to gather opinions and formulate recommendations. The types of questions that should ultimately be explored are:

1. What things turned out well, and why?
2. What tools, techniques, and processes worked well, and why?
3. What improvements would we make to them?
4. What things turned out poorly, and why?
5. What tools, techniques, and processes worked poorly, and why?
6. What improvements would we make to them?
7. What alternatives should we develop?
8. What unexpected problems came up?
9. What warning signs should we have noticed?
10. What decisions could we have reasonably made differently?
11. What still confuses or concerns us?
12. How would we assess the success of this project?
13. How would we assess the success of our tools, techniques, and processes?
14. What are the few key recommendations we would make to management?

Even in non-threatening environments, gathering this sort of input can be a delicate process. It is important that everyone be given the opportunity to speak, and that the meeting not be monopolized by the people with the strongest opinions and loudest voices. As in brain-storming, the early phases should be non-critical:

Let everyone contribute what-ever they think interesting.

You can talk about your own experiences, but you are not allowed to comment on somebody else's experience.

After we have given everybody the opportunity to express all of their thoughts, we can then enter a second phase where we compare, combine, sift, sort, and synthesize punch-lines out of the raw material developed in the first phase.

People are often hesitant to complain about problems or concede errors when their managers are present. Thus, it is often a good idea to conduct separate post-mortem for people at different levels in the management hierarchy. Higher level managers need the output of the post-mortem process to make sure that the needed lessons are learned. It may actually be counter productive for the managers to be present as people are exploring the events of the project.

4. Summary

There is no one best format or technique for post-mortem reviews, and there is no authoritative list of questions to be explored. Every organization has to evolve a post-mortem style that fits in with their culture and mission. Some may involve a weekend of drum circles and trust exercises at a forest retreat, while others are just 30 minutes of prepared power-point presentations in the main conference room.

A good post-mortem meeting is any meeting where people honestly share and explore their experiences with the intent of learning from them and doing better next time. Everything else is just a matter of style.