Own the script, not just the sheet
Run production scripts from a shared or service account owned by the team, not from one person's account. When that person leaves, personal triggers stop and nobody notices.
Protect the data layout
Scripts usually depend on column positions and sheet names. Protect header rows, use named ranges, and look up columns by header text rather than fixed letters.
Make failures visible
- Wrap trigger functions in error handling that logs failures to a dedicated sheet.
- Send an alert email or chat message when a run fails.
- Record the last successful run time where users can see it.
Respect quotas
Apps Script has daily quotas and execution time limits. Batch reads and writes with getValues and setValues instead of cell-by-cell loops, and split long jobs into chunks.
Change control
Keep a copy of the code in version control, test changes on a copy of the sheet, and note each change with a date in the sheet's changelog tab.
Takeaway
Team ownership, protected structure, visible failures and simple change control turn a quick script into a dependable tool.
Frequently asked questions
Why do Apps Script triggers stop working?
Common causes are the owner's account losing access or being removed, authorisation changes, and quota or time limits being exceeded.
How can Apps Script errors be monitored?
Catch errors in trigger functions, log them to a sheet and send an alert email or chat message on failure.
How do you speed up Apps Script on large sheets?
Read and write ranges in batches with getValues and setValues instead of looping cell by cell.