Most people learn a great deal at work and forget most of it. A lessons learned log is a simple record of what happened, what you learned and what you will do differently. Kept regularly, it becomes one of the most powerful and least effortful development goals you can set.
What a lessons learned log is
It is a running document, spreadsheet or notebook where you record short entries after projects, meetings, mistakes or successes. Each entry answers a few questions:
- What happened?
- What went well?
- What did not go well?
- What will I do differently next time?
Project teams often keep lessons learned logs at the end of projects. Keeping a personal one applies the same idea to your own development.
Did you know? NASA maintains a formal Lessons Learned Information System so that experience from one mission informs the next. If lessons learned are worth recording for spaceflight, a few lines after your next project are worth it too.
Why it makes a strong development goal
- It is fully in your control. No budget or approval needed.
- It builds reflection, a skill linked to better judgement and leadership.
- It creates evidence. At review time you have concrete examples of growth.
- It compounds. Patterns emerge after a few months that you would never notice otherwise.
How to write it as a goal
- "Keep a lessons learned log after every client project this year and review it quarterly with my manager, identifying one change to our process each quarter."
- "Record one lesson learned each week for six months and use it to build a checklist for new team members."
The best versions include a review step and an action, so the log leads to change, not just notes.
A simple template
| Date | Situation | What worked | What did not | Next time I will |
|---|---|---|---|---|
| 3 Mar | Client kickoff | Clear agenda sent in advance | Ran over by 30 mins | Timebox each agenda item |
Tips for keeping it going
- Keep entries short. Two or three lines is enough.
- Do it straight after events, while details are fresh.
- Include successes, not just mistakes.
- Review monthly to spot patterns.
- Share selected lessons with your team.
The bottom line
A lessons learned log is a low-effort, high-value development goal that turns experience into growth and evidence. Pair it with a project goal, such as writing a project charter, or with any learning goal. For a structured approach to goals and reviews, see our Business Planning and Goal Setting course.