Everything runs in your browser — nothing is uploaded. If you are new to the tool, follow these steps in order.
1
See what the tool can do
Press Load Sample Project to fill the register with sample lessons. Then scroll down the page:
- Project Information — project name, client, current phase and who keeps the register.
- Summary — counts by severity and status.
- Lessons Learned Register — one row per lesson. Use the Category, Severity, Status and Phase filters above the table to narrow the list.
The first time you open the tool (when there is no data of yours in this browser) the sample is loaded for you, so you can see how it works straight away. Replace it with your own entries, press + New Project / Clear All to start empty, or load your saved project.
Load Sample Data replaces the data in the tool. Save your own work first.
2
See how the data file looks
Press ⇩ Export Table (.csv). It downloads the register as a CSV file that opens in Excel, with these columns:
| Column | What to enter | Example |
|---|
| ID | Your reference | LL-001 |
| Date | YYYY-MM-DD | 2026-04-12 |
| Phase | Initiation, Planning, Execution, Monitoring & Control or Closeout | Execution |
| Category | e.g. Technical / Engineering, Project Management, Commercial / Contracts, Safety / HSE, Quality, Procurement | Quality |
| Lesson Learned | The lesson | Test compaction before each layer |
| Root Cause | Why it happened | |
| Impact Area | Cost, Schedule, Quality, Safety, Scope, Reputation or All | Schedule |
| Severity | High, Medium or Low | Medium |
| Recommendation | What to do next time | |
| Responsible | Owner | QA/QC Manager |
| Status | Open, In Progress or Closed | Open |
3
Enter your own data and import it
Add your own rows under the heading row and save it in excel as csv (comma delimited). Then press ⇧ Import CSV and choose the file.
- Columns are matched by their heading names, so keep the headings (their order does not matter).
- Values that are not in the lists above are replaced with a default (for example Phase becomes Execution).
- Import adds the rows to the register — existing lessons are kept (it asks first).
Excel often changes dates to your local format when it opens a CSV. Before saving, set the date columns to the custom format yyyy-mm-dd, or those dates may be left blank on import.
4
Add, edit and delete rows
You can also work straight in the table on the page at any time, with or without a CSV:
- ＋ Add Lesson adds a blank row. Click any cell to fill it in or change it.
- The × at the end of a row deletes that lesson straight away. There is no undo, so save your register first.
5
Save your project and open it later
💾 Save Register (.json) saves the project information and every lesson in one .json project file. 📂 Load Register opens that file again, on any computer.
The note beside the Save button tells you whether you have unsaved changes or when you last saved. If you try to close or leave the page with unsaved changes, the browser asks you to confirm first (not needed when Autosave is ticked, because your work is kept in this browser).
Use the project file for backups and for sharing with colleagues. Don't edit it by hand.
6
Print, PDF and report
- 🖨 Print / Save as PDF prints the page as you see it, in print-friendly colours. To get a PDF, choose Save as PDF as the printer in the print dialog.
- 📝 Generate Status Report (PDF) opens a formatted lessons learned report in a new tab, ready to print or save as PDF. If nothing opens, allow pop-ups for this site.
7
Other buttons and options
- Autosave in browser (tick box) — while ticked, your work is kept automatically in this browser and comes back the next time you open the page. It stays only on this computer and browser. It is not a backup; use Save Project for that.
- 👁 View Current Data shows the whole register in a window.
- ＋ New Project clears everything and starts a new register (it asks first).
8
Choose the date format
Press 📅 Date format in the toolbar and choose how dates are shown and typed in every date box: DD/MM/YYYY, MM/DD/YYYY, YYYY-MM-DD, DD-MM-YYYY, DD.MM.YYYY or DD-Mon-YYYY. Type a date in that format, or click the 📅 in a date box to pick it from a calendar. A date that doesn't fit the format is outlined in red and not accepted.
The same format is used in the printout and in the generated report and its PDF. It changes only how dates look — your saved project and CSV files are not affected. Your choice is remembered in this browser for every tool on this site.
9
Explore the other tools
Press ☰ All Tools at the top of the page to see every engineering, project management and AI tool on this site, in the same order as the homepage. Type in the search box to find one quickly, then click it to open it. The tool you are using is marked you are here.
The Related tools links at the bottom of this page lead to tools that are often used together with this one.