Every so often I find that a simple SELECT / UPDATE / INSERT statement run by a developer from SSMS, is blocking other processes.
When I investigate this, the specific developer process is an OPEN Transaction. I have spoken to and looked at the developer's query and there is no BEGIN TRAN, so it is not a case of him not committing or rolling back his transaction.
He also does not have AutoCommit disabled in SSMS.
His queries are usually quite simple select of singular insert that completes on his side, but yet it remains as an OPEN TRAN